On September 21, 1989, Olympic gold medalist and light heavyweight champ Michael Spinks shocked the boxing world by defeating heavyweight champion Larry Holmes. The fight was named Upset of the year by The Ring Magazine.
Holmes had taken over duties as heavyweight king from Ken Norton in 1978 via 15 round split decision. Spinks represented Holmes' 19th defense of the title. More significantly, a win against Spinks would tie the undefeated record of the great Rocky Marciano.
Michael Spinks was the reigning WBC, WBA and IBF light heavyweight champion. However, no reigning light heavyweight champ had ever stepped up in weight to take the heavyweight title from a reigning champion.
Spinks was a clear underdog in the fight. He won by narrow unanimous decision with scores of 145-142, 145-142 and 143-142. It was enough to make history for Spinks and prevent Holmes from taking an already legendary career to new heights.