Miracle on Ice (1980): The US ice hockey team, consisting of amateur and collegiate players, defeated the heavily favored Soviet Union team in the Winter Olympics.
Buster Douglas vs. Mike Tyson (1990): James "Buster" Douglas knocked out Mike Tyson, the undefeated heavyweight champion, in one of boxing's biggest upsets.
Leicester City's Premier League Title (2015-2016): Leicester City, a team with 5,000-1 odds at the start of the season, won the English Premier League against powerhouse clubs like Manchester United and Chelsea.
Rulon Gardner vs. Aleksandr Karelin (2000): American wrestler Rulon Gardner defeated Aleksandr Karelin, the undefeated and three-time Olympic champion in Greco-Roman wrestling, at the Sydney Olympics.
Villanova vs. Georgetown (1985): Villanova, an eighth-seeded team, defeated defending champion Georgetown in the NCAA men's basketball championship game, widely considered one of the greatest upsets in college basketball history.
Japan vs. South Africa (2015 Rugby World Cup): Japan, ranked 13th, defeated South Africa, ranked 3rd and two-time World Cup winners, in a stunning upset during the Rugby World Cup.
Greece Euro 2004 Victory: Greece, ranked as outsiders, won the UEFA European Championship by defeating Portugal in the final, shocking the football world.
New York Giants vs. New England Patriots (Super Bowl XLII): The New York Giants, entering as wild cards, defeated the undefeated New England Patriots in Super Bowl XLII, denying the Patriots a perfect season.