Fight of the Century: Muhammad Ali vs. Joe Frazier 1

Joe Frazier, left, hits Muhammad Ali during the 15th round of their heavyweight title fight at New York's Madison Square Garden on March 8, 1971.

Muhammad Ali and his assistant trainer and friend Bundini Brown sing a song in the ring after Ali weighed in at 215 pounds for his bout at Madison Square Garden in New York with heavyweight champion Joe Frazier, March 8, 1971.

Title holder Joe Frazier extends his right army during physical examination in New York on March 8, 1971 before the "Fight of the Century" against Muhammad Ali.

Heavyweight champion Joe Frazier, left, has challenged Muhammad Ali, right, on the ropes during the fourth round of their heavyweight title bout, Monday, March 8, 1971, New York.

Muhammad Ali, red trunks, and Joe Frazier, green trunks, are shown during of their bout in New York's Madison Square Garden, March 8, 1971.

Muhammad Ali, red trunks, and Joe Frazier, green trunks, are shown during of their bout in New York's Madison Square Garden, March 8, 1971.

How big was Ali vs. Frazier 1 at Madison Square Garden on March 8, 1971? Frank Sinatra was a ringside photographer for Life Magazine at the "Fight of the Century."

Boxer Muhammad Ali crouches on the canvas after Ali slipped during the 11th round of the "Fight of the Century" against Joe Frazier on March 8, 1971, at Madison Square Garden.

Muhammad Ali gets knocked down by Joe Frazier in the "Fight of the Century" at Madison Square Garden on March 8, 1971.

Muhammad Ali takes a left from Joe Frazier during the 15th round of their heavyweight title boxing bout in New York on March 8, 1971. Frazier won a unanimous decision.

Joe Frazier, left, hits Muhammad Ali during the 15th round of their heavyweight title fight at New York's Madison Square Garden on March 8, 1971.

American heavyweight boxing champion Joe Frazier, left, against Muhammad Ali in the "Fight of the Century" at the Madison Square Garden on March 8, 1971.

Joe Frazier lands a left to the jaw of Muhammad Ali during their title bout at New York's Madison Square Garden on March 8, 1971. Frazier won on a unanimous decision and retained his heavyweight title.

Heavyweight boxing champion Joe Frazier kept his title at the end of the "Fight of the Century" against Muhammad Ali at the Madison Square Garden, in New York on March 8, 1971.

Heavyweight champion Joe Frazier (L) kept his title at the end of the "Fight of the Century" against Muhammad Ali, at the Madison Square Garden on March 8, 1971.

Joe Frazier stands over Muhammad Ali in the 15th round of their heavyweight title fight at Madison Square Garden on March 8, 1971.

Joe Frazier stands near the fallen Muhammad Ali as referee Art Mercante gestures at left during a boxing match at Madison Square Garden in New York on March 8, 1971. It was Frazier's heavyweight title that was on the line in the bout, but a lot of boxing fans still considered Ali the champion because he was stripped of the title and sent into boxing exile for refusing to be drafted.

Boxer Joe Frazier being directed to the ropes by referee Arthur Marcante after knocking down Muhammad Ali during the 15th round of the title bout at Madison Square Garden in New York on March 8, 1971

Muhammad Ali is down on the canvas after being floored by Joe Frazier in the 15th round of their heavyweight title fight at Madison Square Garden on March 8, 1971. Frazier won on a decision.

A battered Muhammad Ali walks back to his corner as a triumphant Joe Frazier, background, celebrates his title defense after the 15th round of their title bout at New York's Madison Square Garden on March 8, 1971.

Joe Frazier, right, is hugged by his manager, Yancey Durham, after Frazier defeated Muhammad Ali to retain his heavyweight title at Madison Square Garden in New York on March 8, 1971.

A beaten Muhammad Ali is worked over by his handlers following his unsuccessful attempt to take the heavyweight title from Joe Frazier on March, 8, 1971. Frazier retained his title with a uninous decision.

Joe Frazier, a little battered after his title defense against Muhammed Ali, talks with reporters after the fight in New York's Madison Square Garden on March 8, 1971.