PROFESSIONAL BOXING CAREER

Ali's professional debut as a heavyweight came in October 1960 with a six-round decision over Tunney Hunsaker. Ali won his next 18 fights, 15 by knockouts. On February 25, 1964, in Miami Beach, Florida, he waged his first challenge for the heavyweight championship in a match against Sonny Liston.

Although many boxing experts believed Liston was invincible, the brash 22-year old Ali spent the weeks leading up to the fight entertaining reporters and fans with colorfully worded promises of his impending victory. In one of the most stunning upsets in boxing history, Ali delivered his promises: Liston was unable to answer the bell for the start of the seventh round.

Shortly after the fight, Cassius Clay startled the sports world by announcing that he had joined the Nation of Islam and had changed his name to Muhammad Ali. Ali defended his heavyweight crown in nine matches over the next two years. His title was revoked in 1967 when, citing his Islamic faith, he refused induction into the United States military and was sentenced to a five-year prison term. He was released on appeal.

Ali started fighting again in 1970, although the Supreme Court of the United States did not officially reverse his conviction for draft evasion until 1971. Knockout victories over Jerry Quarry and Oscar Bonavena earned Ali a chance to regain his heavyweight crown. But on March 8, 1971, Ali lost a 15-round decision to Joe Frazier.

This was the first loss of Ali’s career. Ali regained the heavyweight championship on October 30, 1974, in Kinshasa, Zaire (now the Democratic Republic of the Congo), with an 8th-round knockout of George Foreman. Over the next four years, Ali defended his title ten times, most famously in a 15-round victory over Frazier on October 1, 1975, in Manila, Philippines, a fight promoted as the “Thrilla in Manila.” On February 15, 1978, in Las Vegas, Nevada, Ali relinquished the crown to Olympic champion Leon Spinks in a 15-round decision. However, he regained the championship on September 15, 1978, prevailing in a 15-round decision over Spinks in their rematch at the Superdome in New Orleans, Louisiana. With this victory, Ali became the first fighter to win the heavyweight crown three times.

Ali announced his retirement from boxing on June 27, 1979, but within a year he challenged the new heavyweight champion, Larry Holmes, for the crown. On October 2, 1980, in Las Vegas, Holmes dealt Ali the worst loss of his career, physically punishing the former champion before delivering a knockout blow in the 11th round. Ali retired permanently in December 1981 after losing a 10-round decision to Trevor Berbick.