Assumed Win

This guy's in a sort of competition -- let's say he ran for school president. When they start to announce the winner, he automatically assumes that he won; he'll stand up, get this smug look on his face and he might even start giving his acceptance speech. But he didn't win... it was his rival, some random underdog, a write-in vote, or a tie, or a mix and match of those things.

The comparable Real Life example is the Award Snub.

Anime & Manga

 * Parodied in Azumanga Daioh. Yukari is announcing the highest scoring person in the class and, despite being the second-lowest scoring person in the class with no chance whatsoever, Tomo stands up just before the announcement. Similarly, earlier, when Chiyo is about to be called forward during the grad ceremony to be recognized for having the highest grades in the school, Yomi has to, repeatedly and with her usual growing irritation, tell Tomo "It's not you!"
 * Penguin Musume Heart has a reversal of this: Penguin gives a heartfelt speech about how Etorufu would make a better student council president then her, and then proceeds to accidentally vote for herself instead.

Comics

 * There's a variant in the X Wing Series comics. Two Rebels compete with two Imperial special forces troopers; whoever gets past the monster and grabs the golden sphere wins for their side. An Imperial got killed, a Rebel gave up his lead to save the other Rebel, and the Imperial got the sphere. Then a heat storm whipped up and killed them all. No, actually that was a virtual reality simulation, though they didn't know that going in. After they'd recovered, the Imperials congratulate the Rebels, smug in their victory. The judge says that maybe the Rebels won, since one saved the other, but when the Rebels are incredulous, he says no, the Imperials won, he was just impressed. It ends up moot anyway, since the Imperial trooper's commander stole the prize, a fugitive who knew something useful, and fled, leaving those troopers behind to be sold into slavery. Luckily for them the Rebels were happy to facilitate a Heel Face Turn.

Film
"Announcer: For the first time in Piston Cup history... Lightning: A rookie has won the Piston Cup. *leaps through paper partition* Announcer: We have a three-way tie! Lightning: *shocked expression*"
 * In a flashback from Austin Powers in Goldmember, Austin was suddenly proclaimed that year's International Man of Mystery instead of Dr. Evil, who was anticipating the award all along.
 * Om Shanti Om: During the parody Filmfare award ceremony, Abhishek Bachchan gets up from his seat fully expecting to win Best Actor... and then the presentors say Om's name. Oops.
 * In Cars: After the first race at the beginning of the movie:


 * In Zoolander, Derek Zoolander has won Male Model of the Year three times in a row. When newcomer rival Hansel (he's so hot right now) is announced as the winner, Derek doesn't notice and assumes he won, going up to the podium and giving an acceptance speech only to be corrected and humiliated in front of the crowd and viewers.
 * The final moment of The Oscar.
 * In the 2007 adaptation of Hairspray, Amber and Tracy are the two most likely to win the title of Miss Teenage Hairspray. As the winner is announced, Amber steps forward with a smile to accept the award, only to find that she lost to

Literature

 * At the end of Winnie the Pooh by AA Milne, Christopher Robin throws a party to reward Pooh for his heroism during a recent flood. Due to the vagueness of his award speech ("This party [...] is a party because of what someone did, and we all know who it was, and it's his party, because of what he did, and I've got a present for him and here it is.") there is some confusion over who the guest of honour is, and Eeyore launches into an acceptance speech before things are straightened out. Something of an oddity, in that Eeyore is not normally the sort to assume that he's the winner; on the contrary, he's so incorrigibly pessimistic that he figures he must be the guest of honour because otherwise he wouldn't have been invited at all.
 * In one of the Babysitters Club books, the members of the eponymous club each coach a regular babysitting charge to appear in a children's beauty contest. The rivalry between the girls is so intense that they can no longer babysit together, but all lose to a heavily made up child beauty queen with several other titles to her name.
 * This also happens in the Little Sister Spin-Off starring Kristy's stepsister, Karen. Her gymnastics teacher is announcing who qualified for a special traveling team, and Karen stands up to greet the teacher and "accept" the invitation right before she reads the last name; one of her classmates grabbed her and yanked her back down before she could embarrass herself further.
 * In A Week In December, R. Tranter thinks he's won the Pizza Palace book award for his biography of an obscure writer, to the point of hearing his own name being read out. His agent has to pull him back to his seat after it turns out that the author of a children's book rather surprisingly won.
 * In All of a Kind Family Uptown, Sarah expects to win the History Prize being given for her graduating class, and her whole family expects it as well given how hard she's studied. Instead, she's crestfallen and humiliated when another girl is called as the winner.
 * In New Moan, a parody of Twilight, Heffa Lump (the book's version of Bella) assumes she's won an award at the end of the book and gets up to accept it. The principal of the school gives her one just to get her off the stage so they can get on with the real awards.

Live Action TV
"Rose: "It's a fix! She's dead! She doesn't need that on her mantel! SHE'S ON HER MANTEL!""
 * Buffy the Vampire Slayer, "Homecoming": Buffy and Cordelia spend the episode competing for the title of Homecoming Queen. At the Homecoming, it turns out there's a tie. Buffy and Cordelia immediately assume that it's the obvious heartwarming ending -- but instead, it's a double Dark Horse Victory. Subverted in the later episode "The Prom", when Buffy's fellow classmates recognize her heroism, though she had expected to be eternally subject to Dude, Where's My Reward?.
 * At the same prom Buffy picked up the "class protector" award, Xander fully expected the Class Clown award. To his disgust, it went to a guy in a Tacky Tuxedo and balloon hat. "Anybody can be a prop class clown!"
 * In one episode of Frasier, the eponymous character has been nominated for an award for his radio show. Initially determined to win, he talks to another character who is due to retire later that year, and so will never again have an opportunity to win the award (having never won it before). Frasier realises that if he does win, he'll be racked with guilt for having prevented the other guy from winning, and so starts to hope that the other guy wins it instead. When it is announced that it is a tie, he is suddenly hopeful, thinking that they could share the award, but the tie turns out to actually be between two previously unseen characters.
 * In another episode of Frasier, restaurant critic Gil Chesterton has received his first award nomination in a category with two other nominees. Once again, the verdict is announced as a tie, leading Gil to fume that he will have to share his award... and, as in the earlier episode, the tie turns out to be between the other two nominees.
 * When The Daily Show gave out its Employee of the Year award for 1999, Stephen Colbert launched into his acceptance speech the second he was named as a nominee. The award goes to a researcher instead; Colbert throws his notes across the room and storms off.
 * A queen of the high school reunion vote is held during an episode of Married... with Children. In it, Al Bundy distracts the entire banquet by getting into a fistfight outside, and comes back several minutes later victorious. The only one left in the room was Peggy... who then broke into the ballot box and removed every vote that wasn't for her. She still acted surprised when she won, while another woman was ready to give her acceptance speech before the winner was declared.
 * Ted Baxter did this in at least one of the "Teddy Awards" episodes of The Mary Tyler Moore Show. Mary herself did it once as well, albeit at Rhoda's urging.
 * On The Muppet Show, Fozzie once was beaten to the title of "Best Comic Bear", by an unknown bear never ever seen before.
 * Appears on Top Gear, when the presenters (having bought used cars and successfully crossed Botswana) sit down to decide whose car was ultimately the best. Richard Hammond clearly expects his 1963 Opel Kadett ("Oliver") to win, since "he" made the journey unmodified, though the car did develop some problems after an unsuccessful attempt to ford a river. The other two presenters give the award to a Volkswagen Beetle instead, as it followed them as the backup vehicle and had no problems at all.
 * Inverted in an episode of Just Shoot Me. Maya gets upset with Jack after she gets him to work for one of the charities she supports, he simply hires workers to do the work, and wins an award. The charity then goes to honor someone else. Convinced it's one of the models, Maya takes to the stage and verbally berates the charity for selling out. It's then revealed that the "someone else" is her.
 * One episode of The Facts of Life played this twice...with the same election. The previous episode had Edna's Edibles holding an election among the girls and Mrs. Garrett. This is put on the back burner when Natalie's father dies. The results of the election are read and Blair starts to take a victory pose when it's announced that Jo actually won. However, Jo becomes overcome with the attention and turns it down, prompting Blair to state that if the winner cannot perform her duties, the title passes to the first runner up. Mrs. Garrett then reveals that she herself is the first runner up. (Blair asks how she did and is told You Don't Want to Know.)
 * In The Golden Girls S6:E14 (Sisters of the Bride), Rose is so certain that she will be the winner of this year's Volunteer Vanguard Award that she spends most of the banquet practicing her acceptance speech and shouts YES! when she hears her name called. Unfortunately, Sophia, who's making the announcement, is only calling on Rose to bring her some water. It turns out that the winner is Agnes Bradshaw, whom Rose expected to beat since Agnes had recently passed away. Rose proceeds to have a meltdown:


 * On an episode of Lizzie McGuire, the eponymous character and Claire are in the running for an election. As the results are announced, both of them stand up only for the winner to be the nerdy Tudgeman.
 * One episode of Pair of Kings featured Lanny stuffing a ballot box with his name so he'd win the King For a Day contest. Lanny was so sure he'd win that, as soon as the winner had been announced, he started giving an order before realizing someone else had been announced as the winner.
 * Kickin It: The Wasabi Warriors once entered a dance contest. When the winner of individual category was to be announced, an arrogant cheater was readying himself to accept it. Then one of the warriors was announced the winner.
 * An clip on America's Funniest Home Videos was taken during a high school ceremony of some sort, perhaps homecoming; one girl was crowned as queen before the announcers realised, oops, the girl next to her had actually won.

Myths & Religion

 * An ancient example: the book of Esther in the Bible. King Ahasuerus asks his evil advisor Haman, "What should be done for the man the king delights to honor?" Thinking he is the man the king is referring to, Haman suggests an elaborate parade. But the man in question turns out to be Mordecai, the hero of the book and Haman's nemesis. And what's more, Haman himself is put in charge of carrying it out.
 * After that, Haman decides to carry out genocide for all the Jews in the kingdom. Nasty guy though, eh?

Newspaper Comics

 * In a Calvin and Hobbes series, Calvin competes in his school's traffic-safety PSA contest. After creating a gory Scare'Em Straight poster, he spends most of the strips taking his victory for granted, culminating in a daydream about the newspaper articles written and statues built in his honor — rudely interrupted by Susie informing him that she won.

Theater

 * While not exactly a contest, there's a point in the DVD version of Andrew Lloyd Webber's Cats where Munkustrap gets ready to laud a particularly worthy cat through song, and Mistoffelees stands up with a flourish... only Munkustrap means Jennyanydots. Mistoffelees shrinks down again like a cat trying to pretend he wasn't after the mouse that got away, and some nearby cats bat at him a bit, grinning.

Web Originals

 * In A Very Potter Musical, Snape is about to read aloud the Gryffindor representative for the House Cup Tournament. When he sees the name, a sly smile crosses his face as he remarks how unusual it is that the representative is a significant person against whom he holds a grudge. Neville starts to stand up to accept the position before Snape snaps at him to sit back down.
 * For a Furcadia contest, creator Graphite made a dream called COLDFusion that turned Furcadia into a game of Atomica, which meant it didn't resemble Furcadia at all. He was absolutely sure he'd win first place--but the judges weren't sure how to rank it. Instead, they created a special category for that dream alone and Graphite was well-rewarded.

Wrestling

 * WWE: as they were announcing the new #1 contender for the WWE Championship, John Cena stood up, assuming he won (justified as he had by far won the fan poll), only for Kurt Angle to say "John... Bradshaw Layfield!"
 * Another time a feud started between Hulk Hogan and Sid Justice because Hogan was named #1 contender for Ric Flair's title, in a press conference where Justice stood up as the announcement was being made.

Western Animation
"Arthur (to Francine, who lost): "Maybe next year you should sing, play the drums, and hop on a pogo stick.""
 * Garfield and Friends, "Caped Avenger": A publisher Jon is trying to impress, seeing Garfield and Odie playing, is inspired with an idea for a comic book that he hires Jon on the spot to write. Garfield immediately starts thinking about royalties and star treatment -- and then it turns out that the new comic book is to be about Odie.
 * The finale of Clone High involves Principal Scudworth bemoaning at being beaten by actor John Stamos for position of Prom King during their high school days, so he sets out to rig the contest of his own school to have a second chance. When the results are finally about to be announced, John Stamos arrives and the rigged automatic voting machine instantly changes the results to the Full House vet.
 * Winx Club, "Dark Sky": Bloom has come to Sky's millenium party, expecting to hear Sky announce her as his girlfiend (as he had promised in the previous episode). Bloom starts to walk up while he's making his speech, but then it ends with him introducing Diaspro instead of her. It turns out that Diaspro has secretly given Sky a potion to make him love her instead.
 * Family Guy: The Celebrity Star (the local news anchor) who was supposed to play Anna in a community production of "King and I" has just quit. Peter's all "We don't need her, we had who we needed all along", and the person who'd originally been cast sees this as Peter giving her the job back and says "Thank you, I'll take the role"... but then it turns out that Peter is playing a robot named A.N.N.A. instead. (Personal note kicker: The contributor for this entry lives in Thailand, and the episode was shown there unedited.)
 * Also, in the episode of Family Guy, where Joe becomes champion of the Special Olympics, and starts neglecting Peter, who helped him, Joe starts naming people who helped him, at an awards ceremony. Many times, Joe starts off by saying something that describes Peter, but ends up calling someone completely different.
 * Nigel Uno suffers this indignity twice in the Codename: Kids Next Door episode "Operation Elections", first when the 4th grade secretary announces the Delightfuls as winners of the presidential election he was running for (he had already prepared a speech which referenced some previous episodes' events, and was walking out to the podium as soon as the secretary said "And now, meet your new president"), and then at the end when he's told (while he's making his speech) that Eggbert Eggelstein won (even though the secretary had told him earlier that Nigel did win: it turns out he only said that so Nigel could break him out of detention).
 * And Nigel isn't even the all time "leader": In The SpongeBob SquarePants Movie, Mr Krabs announces that the new manager of the Krusty Krab 2 has "a name you all know, it starts with an S!". Spongebob assumes the best, but has to humiliate himself three times over microphone before realising that the new manager is actually Squidward.
 * Played for laughs in The Simpsons episode "The Mansion Family", in which Homer is the only person who does not earn a Springfield Pride Award. He gasps in anticipation when it is said the next winner "brings laughter and joy to the children of Springfield", even though he is not known for anything like that. He still stands up and adjusts his tie when it is said the winner has a "red nose" and "baggy pants" and it is not until the winner's name is announced that he realises he has not won.
 * The B-plot of "Lisa's Substitute" has Bart running for class president, and declaring where his victory party will be held at the moment the polls are opened. Unfortunately, everyone's so busy celebrating that they forget to vote, leading to Martin Prince's moment of triumph with a parody of the "Dewey Defeats Truman" headline mentioned above.
 * One more example: When Miss Krabbaple has been nominated for a teacher's award, she is saying how this couldn't be possible without the support of just one person. This is in front of a group of people outside the school, and Principal Skinner walks up to the podium to acknowledge this, smiling, but once Bart's name is announced, he keeps walking and grinning to avoid embarrassment.
 * At the beginning of "Deep Space Homer", he's expecting the "Worker of the Week" award because every other worker already received it -- but instead, it goes to an inanimate carbon rod.
 * This occurs in CatDog twice in one episode. Cat, the intelligent and well read main character, auditions for a play about Abraham Lincoln, believing himself to be an incredible actor but ends up losing and humiliating himself when Dog, The Ditz, wins the part by a landslide. Cat, thoroughly incensed, sabotages Dog's health in order to win the part and ends up succeeding due to Dog being incapacitated by his illness. Thus, Cat stars as the leading role as Abraham Lincoln and ends up doing an amazing job, earning a standing ovation for his performance. Later at an award ceremony, Cat awaits his award for best actor, knowing that he deserved it because of his skill and finesse and thus, makes his speech before the award is even given out. The award goes to Dog instead, for his amazing performance as Abraham Lincoln's mute steed and it turns out that the standing ovation from before was all for Dog.
 * Played for laughs in Futurama when Leela wins an intergalactic beauty pageant despite having nothing to do with the pageant only to find that the announcer, Zapp Brannigan, simply yelled her name in surprise while he was trying to open the winning envelope. "What are you people, idiots?"
 * Of course, in another episode, Zapp declared her the winner of a limbo contest she didn't enter, so, y'know...
 * From Jem and The Holograms, "Hollywood Jem: Part 2 - And The Winner Is..." has Kimber Benton assuming Jerrica "Jem" Benton is going to win an Oscar for Starbright, but an older, more experienced actress that had given Jem a hard time in the press wins the award --and her speech includes an apology for how badly she treated Jem.
 * Not a winner trope per se, but in one Kim Possible episode they were going to have an exchange student sent to Japan. Did the Japan fanboy who stood up get the place? No, it was Ron Stoppable, who essentially got A Day in the Limelight.
 * The eponymous Kim Possible had this happen to herself, after Bonnie was implied to have rigged the homecoming Queen vote in her favour, or at least knew about it beforehand.
 * Also during the Talent Show episode, Kim competed, and both she and Bonnie assumed they would win, when the prize went to Ron Stoppable, the judge citing quantity over quality.
 * In the Recess episode 'Principal For A Day." When the faculty draws a sudents name out of a box to be principal for a day Randall stands up thinking he won (because he stuffed the box). The actual winner is TJ.
 * Played for laughs on Arthur when George, whose performance we never actually saw, won the school talent show with some kind of pogo-stick act. Lampshaded seasons later when George won again (complete with Stock Footage of the award announcement).


 * Another episode had Michelle Kwan come to present an Athlete of the Year award. Everyone assumed Francine would win, including herself. To their surprise, Jenna won instead. The shock of the announcement took a while to sink in for Francine, who stood up and thanked everyone anyway.
 * On Teachers Pet, both Leonard and Scott are shocked when the class presidency goes to Ian.
 * Bugs Bunny in the 1943 cartoon What's Cookin', Doc? He's so sure he's going to win the Academy Award that he's already up on stage next to the host (whose shadow we see as he delivers his spiel), who, to Bugs' shock, announces the winner is James Cagney. Also, in the later cartoon This Is a Life?, Daffy Duck thinks the weekly testimonial will be about him when it turns out to be about Bugs.

Real Life

 * An apocryphal Real Life story: After an 1883 chess tournament, a toast was proposed "to the best player in the world." Both Wilhelm Steinitz and Johannes Zukertort stood up to thank the toastmaster. In 1886, Steinitz defeated Zukertort to become the first World Champion.
 * During the 1934 Academy Awards, both Frank Capra and Frank Lloyd were up for the award for Best Director (Capra for Lady for a Day, Lloyd for Calvacade). When the announcer said "Come up and get it, Frank", both Lloyd and Capra went up to accept the Oscar. Much to Capra's chagrin, Lloyd was the real winner. (The Oscar, see above, may be a reference to this.)
 * The 2006 Country Music Awards saw Faith Hill and Carrie Underwood both nominated for Female Vocalist of the Year. As the nominations were being announced, a camera was trained on all five finalists, including Hill and Underwood. Then, as Underwood was announced the winner, Hill smiled and raised her arms, then apparently screamed "What?" and stormed away. All of this was caught on live television just before the nominee camera shots were pulled away. Faith Hill and her management insisted the act was a joke, but left many unconvinced. Her career nosedived not long after.
 * However, the king of all real life examples of this trope came from the 1948 presidential election, when the Chicago Tribune, forced to print earlier due to an ongoing strike against the Taft-Hartley act, used incomplete poll data to generate their headline: "Dewey Defeats Truman". Harry S Truman famously posed with the incorrect newspaper, but we can assume that Thomas E. Dewey was not so enchanted.
 * Funny how the lesson wasn't learned in 2000, where networks were prematurely calling the election for Bush and then Gore and then Bush again, and many newspapers had to scramble to reprint the front page headline.
 * An earlier example from the 1916 election: Republican challenger Charles Evans Hughes went to bed believing that he had won the election, but late returns from California showed that Woodrow Wilson had carried the state, and thereby the Electoral College. A reporter who called to ask Hughes for his reaction was told by a servant "The president-elect has retired and does not wish to be disturbed." The reporter replied, "When the president-elect is available, please tell him that he is not the president-elect."
 * This happened in the final round of the 1950 FIFA World Cup in Brazil:
 * Following emphatic wins over Sweden and Spain in the final round robin group of four, red-hot favourites Brazil merely had to avoid losing their final match against second-placed Uruguay to win the World Cup. An impromptu carnival was held in Rio de Janeiro, with revellers holding signs already proclaiming Brazil the champions, and some 200,000 people packed into the Maracana Stadium to watch the match. FIFA president Jules Rimet prepared a Portuguese-language speech for the trophy presentation, the Brazilian Football Confederation struck 22 gold medals for the players (at the time, individual players did not receive winner's medals from FIFA), and a celebratory song called "Brazil the Victors" was written to be performed after the win.
 * Then came the game itself... Friaca opened the scoring for Brazil just after half time, and the mostly Brazilian crowd went wild. Uruguay's Juan Alberto Schiaffino equalised twenty minutes later; the crowd spirit was dampened, but only temporarily as a draw still favoured Brazil. But then Alcides Ghiggia put Uruguay in front in the 79th minute, and the crowd went completely silent. Uruguay held on to win the match. Several Brazilian spectators either suffered heart attacks or jumped to their deaths from the top of the stadium, Rimet had to throw away his prepared speech and awkwardly hand over the trophy to Uruguayan captain Obdulio Varela with no ceremony, the winners' medals were melted down, and "Brazil the Victors" was never performed. The match is nicknamed the "Maracanazo", or "Maracanã Blow", in Latin America.
 * Several years ago, both Susan Flannery (from The Bold & The Beautiful and Susan Lucci (from All My Children) were nominated for the Best Actress Daytime Emmy. When the winner was announced, the presenters voices were garbled and the band began playing All My Children's theme. With numerous people pointing at her, Susan Lucci assumed she was the winner and began to walk on stage. Problem is, it was FLANNERY who had won. Luckily, Lucci was able to back off the stage before appearing on-camera. And even luckier, she had finally won her elusive Emmy several years prior, otherwise the incident would have been much more embarrassing for all involved.
 * Arena Football, 2005 playoffs: Chicago trails Colorado by 3 on the final play of the game. Colorado intercepts Chicago's pass, and the confetti flies... but there's a penalty on the play on Colorado, so crew have to clean up the confetti before Chicago kicks in a game tying-field goal. Colorado cleans up in overtime with a touchdown. Video.
 * Australia's Next Top Model had a related incident when they actually announced the wrong person as the winner, and she'd already done her acceptance speech when the host revealed that in fact, the other finalist had won.
 * The 1986 World Series. Red Sox vs. Mets. Going into game six, the Red Sox lead three games to two. The Red Sox pulled ahead, 5-3, in the top of the tenth inning, and after quickly striking out the first two batters and getting two strikes against third batter Gary Carter, it looked like they had it in the bag: the scoreboard at Shea Stadium flashed, "Congratulations, Boston Red Sox, 1986 World Champions", and TV announcers were remarking that Red Sox pitcher Bruce Hurst was about to be named series MVP. And then, things took a turn. First, Carter singled. Next up, Kevin Mitchell, also singled. Next up, Ray Knight singled, Carter ran home and Mitchell moved to third. Pitcher Calvin Schiraldi was pulled off the mound and replaced with Bob Stanley. Next up, Mookie Wilson, hit a foul ball that let Knight move to second and Mitchell score, tying the game. Although all of this was bad for the Red Sox fans, what happened next is the event on which they pin all the blame: Wilson then hit a ground ball to first base, which went through first baseman Bill Buckner's legs. Knight scored, the Mets won 6-5, which tied the series 3-3, forced a Game 7 (which the Mets won), turned Buckner's name into a curse word among Red Sox fans, and gave fuel to the idea that the Red Sox had been cursed.
 * Inverted in an Airdrie, Alberta, Canada high school. A student, convinced he would not win a cash award for attendance, declined to attend the draw and stayed in class instead. Then the teacher got a call over the school phone network, and sent the student down to the stadium--the student had won a $1,000 draw.