On May 25, 1965, Muhammad Ali triumphed in one of the fastest and most controversial heavyweight fights in boxing history.
In a rematch with Sonny Liston, Ali danced around the ring for most of the fight before landing a punch to Liston's jaw that dropped him stunned to the ground. Liston eventually did get up as Ali celebrated his victory prematurely, and the fight then resumed.
Ali went in to finish Liston off, unleashing a torrent of punches. In the middle of that barrage, the referee intervened and said the fight was over, awarding Ali a KO victory even though Liston was still fighting. Apparently, the scorekeeper had already counted Liston out for being down on the mat for too long, but the message was delayed in reaching the referee.
As a result, the crowd booed, and many theories have arisen as to whether the match was fixed beforehand.
You can see the entire fight here: