Cassius Clay (a.k.a. Muhammad Ali) Becomes World Heavyweight Champion (1964): On February 25, 1964, Muhammad Ali, then still known as Cassius Clay, fought Charles "Sonny" Liston for the world heavyweight title in Miami, Florida.
Liston expected an early knockout. However, Muhammad Ali was a lot faster than most other boxers. Ali's plan was to dance around the powerful Liston until Liston tired out. Ali's plan worked.
By the 6th round, Liston was exhausted. He had also hurt his shoulder and was worried about a cut under his eye. When the bell for round seven rang, Liston shocked everyone when he refused to continue the fight. Muhammad Ali was declared the winner and became the heavyweight boxing champion of the world.
See full article: Muhammad Ali