Frazier won the undisputed heavyweight title with a 15 - round unanimous decision over Ali at Madison Square Garden in an extravaganza known as the Fight of the Century .
Joe Frazier knocks down Muhammad Ali in the 15th round of their first fight , March 8 , 1971 .
Joe Frazier won the undisputed heavyweight title with a 15 - round unanimous decision over Muhammad Ali at Madison Square Garden in an extravaganza known as the Fight of the Century .
Joe Frazier knocks down Muhammad Ali in the 15th round of their first fight , March 8 , 1971 .