A 20-year-old Mike Tyson destroyed Trevor Berbick in just 2 rounds to become the youngest heavyweight champion in history. The knockout was so devastating that Berbick struggled to get back to his feet, stumbling around the ring.
In their fourth fight, Sugar Ray Robinson landed what many consider the perfect left hook to knockout Gene Fullmer and regain the middleweight title. The punch came out of nowhere and ended the fight instantly.
At 45 years old, George Foreman became the oldest heavyweight champion by knocking out Michael Moorer with a devastating right hand. Foreman was losing the fight on points before landing the fight-ending punch.
Manny Pacquiao delivered a devastating left hand that knocked Ricky Hatton out cold in the second round. The punch was so powerful that Hatton was unconscious before he hit the canvas.
Thomas "The Hitman" Hearns delivered a devastating right hand that knocked the legendary Roberto Durán out cold in the second round. This punch is often considered one of the most powerful in boxing history.
Rocky Marciano knocked out Jersey Joe Walcott with his famous "Suzie Q" right hand to win the heavyweight championship. Marciano was behind on all scorecards when he landed the devastating punch.
Julian "The Hawk" Jackson delivered one of the most devastating knockouts in middleweight history against Herol Graham. Jackson was losing the fight when he landed a monstrous right hand that knocked Graham out cold.