Basic Trope: A third party wins in a competition that two people were very much into.
Straight: Bob and Alice are participating in the T. Roper High School Talent Show, and both are bitter rivals. At the end of the night, though, the trophy is given to Charlie, who neither of them knew.
Exaggerated: Bob and Alice have been training for the talent show for months, and Charlie just shows up at the last minute - but still wins.
Justified: The judges were split on Bob and Alice's fairly similar routines, but Charlie's was different enough to win the lion's share of votes.
Charlie has trained for months and months, but the trophy goes to Alice or Bob.
Alternatively, Alice and Bob each want to lose a competition. Both try to lose purposely, and try to make the other one win. In the end Charlie wins, satisfying all three of them.
The trophy goes to either Alice or Bob, causing the runner-up to graciously accept defeat.
Alternatively, when it's time to announce the winner they say "Charlie! YOU...didn't win," making the viewer think that Charlie was about to win.
Double Subverted: That trophy was given out due to an error. Charlie won for real.
Bob and Alice's skits were lavishly produced and Charlie's was clearly thrown together in the eleventh hour. And yet he still wins.
Charlie does not prepare at all. He is stuck in the competition and still wins, due to the fact that he is the hero.
Zig Zagged: The judges are going to nominate Charlie for the win. But then, the judges realize that Alice's routine had some things that weren't originally seen. But then, after some thinking they agree that Charlie's routine is best. But here comes Bob, at the last minute...
Averted: Either Bob or Alice wins the trophy.
Enforced: "We need to put the rivalry into perspective by having a third party win everything!"
Lampshaded: "Wait...he won? But...I trained for so long..."
Invoked: The judges, noticing how angry Alice and Bob are at each other, conspire to give Charlie the trophy to teach them a lesson.
Defied: "However, despite what lessons we may want to teach, the winner is..."
Bob and Alice don't resolve anything by losing...both are just as bitter as they once were.
Bob and Alice do end up forgetting about their rivalry, but only because they've turned their animosity for each other onto Charlie.
Reconstructed: Bob and Alice put everything into perspective and realize that they were the only ones who cared about their rivalry. This causes them to become friends.