Joe Frazier turned pro under the guidance of Yank Durham in 1965 and ran off 11 straight wins until he ran into tough guy Oscar Bonavena, in September 1966. The Argentine dropped Frazier twice in one round, but Smokin’ Joe came off the deckk–showing the Madison Square Garden crowd the heart and character that would mark his career–to win a 10-round unanimous decision.

After Bonavena, Joe Frazier knocked out contenders Doug Jones (KO 5), George Chuvalo (TKO 4) and closed out the ‘67 campaign with a 19-0 career record.

With Muhammed Ali’s exile from the sport, the heavyweight division was in disarray. While the WBA held an examination tournament, Frazier was matched with his nemesis from his amateur days, Buster Mathis, for the New York State world title on March 4, 1968 at the Garden.

This time Mathis was not able to dance his way to victory over three rounds. A relentless Frazier wore down the bigger, heavier man, and stopped in the 11th round. From 1968-70, Frazier made six defenses, including a fifth-round TKO of WBA champ Ali was granted a license to fight and the demand quickly grew for a showdown between the former undefeated champ and the reigning king.

In the fall of 1970, Ali knocked out top contenders Jerry Quarry and Bonavena, setting the stage for the most anticipated heavyweight title fight since the Louis-Conn rematch of 1946.

Each fighter was paid the then-unheard of purse of $2.5 million. The build up to the fight was unparalleled in boxing history; transcending the sport–and the sporting world. On march 8, 1971, before a sellout crowd at Madison Square Garden, the twon waged one of the greatest heavyweight battles ever. In the 15th round, Frazier landed perhaps the most famous left hook in history, catching Ali on the jaw and dropping the former champ for a four-count. At the end of 15 grueling rounds, Joe Frazier got the nod from all three judges and left the ring as the undisputed champ.

But the fight took a lot out of Frazier, who didn’t fight again the rest of the year. In 1972, he defeated against two journeymen. His reign as champion ended in January of 1973, against George Foreman in Kingston, Jamaica. Foreman dropped Frazier six times before the fight was stopped in Round 2.

He beat Joe Bugner in his next fight, but dropped a 12-round decision to Ali in their rematch in January of 1974. He got back on the winning track to set the stage for a rubbermatch with Ali, who had since lifted the title from Foreman.

In the suffocating heat in Quezon City, just outside the Philippines capital of Manila, the two aging warriors dueled for 14 rounds, before Frazier found his rhythm in the middle frames and attacked the champ’s body with both hands. But Ali turned the tide for good in the 10th and won the next four rounds. By the end of the 14th, both fighters were exhausted, but Frazier’s eyes were nearly swollen shut, and his corner stopped the bout. Later, Ali said, "It was the closest I’ve come to death."

Nine months later, Frazier tried to fight himself back into title contention with a rematch against Foreman, but was stopped in five rounds. He retired following the second Foreman fight. Five years later he launched a one-bout comeback, but drew with a journeyman, Jumbo Cummings, before hanging up the gloves for good.