The Sore Loser (usually it's a sore loser, but not always) is not pleased that they lost the big game, got a bad call from a referee, or were humiliated in front of spectators. So what do they do? They decide to physically assault the offender after the game has ended and everyone's gone home. They usually intend to inflict a No-Holds-Barred Beatdown and/or Curb-Stomp Battle on the offender.
As the examples show, it usually does not go well for the instigator of this trope. Usually, it turns out to be the assailant that ends up on the receiving end, adding to their Humiliation Conga. This can serve as An Aesop about sportsmanship and accepting defeat.
Expect to see this trope in sports related media (bonus points if it's a combat sport like boxing, karate, MMA, etc). Note that this trope doesn't have to happen immediately after the contest. It can take place beforehand or in between events.
If the violence happens inside the playing area during the game, it's Unnecessary Roughness. If the violence happens outside the playing area during the game, it's Ring Out. If the fans are the violent ones, it's Football Hooligans. If the intent is to injure the opponents to hamper their skills & abilities, it's Crippling the Competition.
- In the Dressrosa arc of One Piece (specifically during the Corrida Colosseum tournament), after losing to Rebecca in the Round D match, the tournament losers tried to assault her when she's about to play in the next round. Fortunately, Diamante (the event organizer of the colosseum) stops them short, saying that Rebecca won by the rules.
- In Genkai's disciple selection test early on in YuYu Hakusho, she has all her applicants get lots of paper. If their paper changed color, they could start her selection trials. If not, they were told to leave. Two self-proclaimed experts angrily attack Genkai over being rejected. She promptly blasts them with spirit energy across the courtyard and into her entrance gate. (It turns out that her paper lots were not random; they only changed color if those holding them had a certain amount of spirit energy.)
- Double subverted in a later episode of Sailor Moon; Haruka wins a motorcycle race and other bikers plan to attack her. One of her more honorable opponents warns them to stay away. But later on, bikers riding in a truck attempt to run Haurka and Usagi off the road; they then attack Haruka afterwards, but she easily mops the floor with them.
- Subverted in IGPX: Immortal Grand Prix. Team Satomi manages to beat Sledge Mamma, despite mechanical sabotage during the race. The team thought this was something Sledge Mamma would do, since they usually use underhanded tactics. After the race, Takeshi, Liz, and Amy are ambushed by a group of thugs who had previously hassled Takeshi. Sledge Mamma showed up behind them, leaving Satomi trapped between two. Satomi feared the worst. The thugs attack, but are quickly beaten down by Sledge Mamma. The thugs admit to being Sledge Mamma fans, but Yamma tells them that what they did was despicable.
Yamma: Sorry about that. Our fans can get a little rowdy sometimes. We just wanna beat ya, not beat you up.
- In the Pokémon episode "The Flame Pokémon-athon," this happens after Dario fails to win a race, despite such tactics as Crippling the Competition, and Ash is the winner instead. Dario and his Dodrio immediately attack Ash and the Rapidash he's riding—and promptly get kicked into the stratosphere.
- During Pokémon League tournaments, it's against the rules for competing trainers and their Pokémon to pick fights with each other outside of official matches.
- Yu-Gi-Oh!: Furious at losing to Yugi, Panik snaps and retaliates with flamethrowers. Fortunately for Yugi, and unfortunately for Panik, the Millennium Puzzle beats fire any day of the week, and Panik is Mind Raped for his tantrum.
Panik: I may not have defeated you, Yugi...BUT I CAN STILL ELIMINATE YOUUUUUUUUU!
- Medaka Box: Intentionally used by Kumagawa Misogi in the first match of the Election Battles. Standing on a precarious grating slowly falling into a pit of snakes until someone surrenders, Kumagawa concedes the match... and then just keeps attacking his opponent anyway. Why does he get away with this? Two reasons; one, since the match is over, this is a private quarrel that the Election Committee can't interfere with. And two, nobody can jump down after them without making the grating fall down to the venomous snakes immediately.
- In the second 3 Ninjas film 3 Ninjas Kick Back, the defeated baseball team goes for "extra innings" - that is, attack the victorious players and their friend, Miyo. One of the boys decides to fight Miyo, but it does not end well for him.
- From the The Karate Kid franchise:
- In The Karate Kid Part II, John Kreese does this to his losing students after they were beaten by Daniel in the first movie. He yells at them and gets physical until Mr. Miyagi intervenes. Like the above 3 Ninjas example, it doesn't go well for Kreese.
- The alternate ending to The Karate Kid (2010) remake has Master Li do the same after his students lose to Dre. Mr. Han intervenes and trashes Li in a fight, contributing to his Humiliation Conga.
- The 1995 martial arts movie A Dangerous Place has the hero, Ethan (played by TJ Roberts of Masked Rider), face the villain, Taylor Dylan (played by Corey Feldman), in a karate tournament. Ethan learned earlier that Dylan had been responsible for the death of his brother, driving him to fight harder and win. Dylan then makes a break for it to avoid arrest but is chased and cornered again by Ethan. The two fight again, this time without rules. Ethan trashes Dylan but decides to let him live, having the police arrest him.
- Another martial arts B-movie from 1995, Equal Impact, opens up with a beaten competitor from the Northwest Karate Tournament trying to fight the protagonist in the parking lot.
- Subverted in The Mighty Ducks second movie. A trio of players from the Hawks, still bitter about their defeat in the previous movie, spot the Ducks out and about while skating. The three set up a trap intended to humiliate the Ducks, only to encounter Fulton Reed who stops them.
- Happens in Unseen Academicals, when Andy decides to get his revenge on the book's heroes. Fortunately, Pepe knows Andy's kind, and was waiting for him.
- In book one of A Song of Ice and Fire, Ser Gregor Clegane is not pleased that he was beaten by Ser Loras Tyrell in the joust...he shows this displeasure by half decapitating his own horse and trying to kill Loras Tyrell with his greatsword. His brother Sandor saves Loras, but Gregor keeps attacking until King Robert intercedes.
- In Jeeves and Wooster, after Barmy wins a golf game by means of a gizmo, Bertie plots to puncture his hot water bottle in the night. He gets the wrong room, and hilarity ensues.
- An episode of Criminal Minds had an unsub who was in a Fight Club. After losing one too many fights, he sneaks up on the man who beat him and shoots him. He enjoys the feeling of power he gets from it, so he continues attacking authority figures.
- The Four Horsemen once ambushed Dusty Rhodes while he was going to the office and beat his arm with a baseball bat, breaking it.
- In an infamous segment on WWE Raw "Stone Cold" Steve Austin broke into Brian Pillman's house. Pillman was armed with a gun, and the screen went black just before a gunshot.
- Generally speaking it's fairly common for a heel to lose a match and more or less immediately beat the crap out of his-or-her victorious opponent.
- In the Formula Rejects Alternate Series, it was quite common for displeased drivers to fight other drivers or team personnel after or even during a race (after they had dropped out, obviously). This has become less common with time, but still happens if the situation justifies it.
- The Neo Geo title Legend of Success Joe has Joe not only boxing with opponents in the ring but also fighting it out with boxers and Mooks outside of the arena in between boxing matches.
- Jak and Daxter. In Jak II, after losing the hoverbike racing championship to Jak, Errol attempts to run him down. However, Jak jumps out of the way causing the enraged Krimzon Guard commander to crash into several barrels of dark eco that Jak won, thus only hurting himself.
- Golden Sun has a battle tournament that Isaac competes in and wins. If you transfer your save data over to the sequel, the gladiators that Isaac fought will show up in the game and are still sore that they lost to a "cheater". They attack Felix (even if Isaac isn't around to extract their revenge upon), but they are soundly beaten by Felix's party and give you an item.
- During Chapter 3 in Paper Mario: The Thousand-Year Door, your first match in the Glitz Pit is against a gang of Goombas that attack Mario during the announcer's introduction of the combatants. They are easily beaten. Halfway through the tournament, the Goombas ambush Mario after he finished his previous fight in attempt to beat him while he's worn down since they're still sore about losing to him earlier. Mario quickly trounces them without breaking a sweat.
- Steins;Gate: After Faris defeats Shido in the Rai-Net Tournament, he sends his team to kill her and Okabe in retaliation.
- The Simpsons: Bart plays an arcade game called "Hockey Dad" loosely based on the real life phenomenon where the parent of a player, thinking that the referee made a bad call, confronts & assaults the ref either during the game or afterwards.
- Avatar: The Last Airbender: Zuko defeats Zhao in an Agni Kai duel but doesn't kill him or leave him scarred. Satisfied with his victory Zuko walks away only for Zhao to get enraged and try striking while his back is turned. Iroh intervenes and knocks Zhao back to the ground, admonishing him for his disgraceful and dishonorable display in defeat.
- Family Guy had an episode where Peter is teaching Chris how cultured Americans are and that part of that is getting way too emotionally involved in high school football. He then teaches him that sometimes your team loses and you have to beat up the referee in the parking lot afterwards. However, in the middle of the beating, Peter realizes that the referee is an old friend of his, and the two have a pleasant conversation even as Peter keeps beating the shit out of him! He even has Chris come in and say hello, while taking over the beating.
- A loss from a basketball game in Houston, Texas turned deadly when someone shot and killed one of the winning players soon after.
- This trope can happen during the game too. Manchester United star Eric Cantona took direct retribution on a fan who was heckling him during the 1994-1995 season. Cantona famously leapt into the crowd and delivered a roundhouse kick to the chest; he was banned from all football for a year and faced a criminal investigation. Man U fans still sing about this when playing Crystal Palace.
- Former New England Patriots general manager Patrick Sullivan found himself in the middle of this during the 1985 NFL playoffs when New England defeated the Los Angeles Raiders in the AFC Divisional playoffs. Sullivan had repeatedly heckled the Raiders' best pass-rusher, Howie Long, during the game; and as soon as play ended Raider linebacker Matt Millen decked Sullivan with Millen's helmet.