Joe Frazier, the relentless slugger who became the heavyweight champion of the world and earned boxing immortality with three epic battles against Muhammad Ali, died on Monday at age 67, his personal manager said.

"Smokin' Joe" Frazier, who was the first boxer to beat Ali, died in Philadelphia a month after being diagnosed with liver cancer. Leslie Wolff, Frazier's personal manager, confirmed his death.

Frazier won the Olympic heavyweight boxing gold medal for the United States in 1964 in Tokyo and held the world heavyweight boxing crown from 1970 to 1973.

He is eternally linked with Ali thanks to their trilogy of fights in the 1970s, among the most famous in the history of the sport. Frazier won the first and Ali took the next two.

While both fighters were American blacks and Olympic gold medalists, their personalities could not have been more different. Ali was a charismatic self-promoter. Frazier was a proud, no-nonsense man who dropped out of school at age 13.

Frazier won the world heavyweight title in 1970, knocking out champion Jimmy Ellis, after Ali had been stripped of the championship in 1967 for refusing to fight in the Vietnam War due to his Muslim beliefs.

Ali was reinstated in boxing and met Frazier on March 8, 1971 at New York's Madison Square Garden, in a bout billed as "The Fight of the Century." Frazier sent Ali to the canvas with a left hook in the 15th round. Ali got up but Frazier won by unanimous decision.

The brutal encounter left both men hospitalized. Frazier later lost his title in 1973 to hard-hitting George Foreman.

The second Ali-Frazier fight was on January 28, 1974, again at Madison Square Garden, with Ali winning a 12-round decision.

Ali then beat Foreman to reclaim the championship. He defended it in the third Frazier fight on October 1, 1975, in an encounter in the Philippines known as "The Thrilla in Manila" - one of the most famous sporting events of the 20th century.

Factbox about Joe Frazier

* Born January 12, 1944, in Beaufort, South Carolina.

* Won the Olympic heavyweight boxing gold medal for the United States in 1964 in Tokyo.

* Won the world heavyweight title in 1970 after knocking out champion Jimmy Ellis.

* Hands Muhammad Ali the first defeat of his pro career on March 8, 1971, winning a 15-round bout at New York's Madison Square Garden billed as "The Fight of the Century."

* Lost his title in 1973 to hard-hitting George Foreman.

* Frazier loses second fight with Ali, again at Madison Square Garden, in a 12-round decision on January 28, 1974.

* In one of the most famous sporting events of the 20th century, Frazier lost to Ali in a brutal encounter in the Philippines known as "The Thrilla in Manila" on a technical knockout when trainer Eddie Futch would not allow Frazier to fight the 15th round.

* Inducted into International Boxing Hall of Fame in 1990.

* Frazier retired in 1976 before staging an unsuccessful return in 1981.

* Career record of 32-4-1 with 27 knockouts.