On this day in 1964, Cassius Clay stunned fight fans when he knocked out world heavyweight boxing champion Sonny Liston. The fight ended in a 7th-round technical knockout.

Who Was Sonny Liston? Liston had twice defeated former champion Floyd Patterson in one round. He was an 8-to-1 favorite. Liston thought Clay was a mouthy upstart. And he promised to put his fist so far down Clay's throat, he was going to have trouble removing it.

Quick Feet, Quick Mouth. Cassius Clay was a quick-footed 22-year old fighter given to exaggeration, poetry, and joking around. He predicted that he would knock out Liston in the 8th round because he could "float like a butterfly, sting like a bee." By the 7th round, Liston complained of a hurt shoulder, and didn't respond to the seventh-round bell.

New Champ. Liston's non-appearance caused the title of heavyweight champion of the world to go to Cassius Clay.

Cassius Clay. A Brief Bio. Cassius Marcellus Clay Jr. was born in Louisville, Kentucky, in 1942. When he was 12, he started boxing. By the time he was 18, he had racked up 100 wins in amateur competition, won the International Golden Gloves heavyweight title, and taken a gold medal in the light heavyweight category at the Rome Summer Olympic Games.

A Word About the Olympic Games. When Liston won the gold, boxing experts of the time didn't actually think much of his skills. His style was non-traditional. Rather than use the traditional defense move of slipping a punch, Liston swayed backward, bending at the waist and avoiding it. The pros were appalled.

Go Pro. Clay turned professional after the Olympic Games. In his first 19 matches, he was undefeated, which gave him the right to challenge Sonny Liston. Liston had held the world heavyweight title since 1962 when he defeated Floyd Patterson .

On This Day in 1964... a crowd of 8,300 spectators gathered at the Convention Hall arena in Miami Beach. They wanted to see if Cassius Clay ~ who had earned the nickname of the "Louisville Lip" ~ was all talk and no action. He wasn't. For all his bragging, Clay could do what he said. He danced and wove, avoiding Liston's power punches as he pummeled Liston with quick jabs to the head.

First Round. Liston hurt his shoulder in the first round by swinging for and missing his target. Clay was skilled at moving instead of being hit. By the time Liston threw in the towel between the sixth and seventh rounds, the two fighters were matched for points.

Changes in Attitudes... To celebrate his victory, Clay went to a private party at a Miami hotel. Also attending was Clay's friend Malcolm X (see Today Only for February 21), a leader of the African American Muslim group, AKA the Nation of Islam. Two days later, Clay dropped his blustering and announced he was joining the Nation of Islam. He stood up for their beliefs of racial segregation and talked about the importance of the Muslim religion in his life.

Name Changes. Later that year, Clay rejected his family name, which he said was his slave name, and took the Muslim name of Muhammad Ali. He said "I don't have to be what you want me to be; I'm free to be what I want"

And Muhammad Ali... went on to become a great figure of 20th century sports. He successfully defended his title nine times.

Feeling a Draft. His title was taken from him when he refused to be inducted into the US Army. His reason: he was a devout Muslim minister, which he felt qualified him for conscientious objector status. He was sentenced to five years in prison for violating the Selective Service Act. He appealed the decision and was allowed to remain free. His comment, "I ain't got no quarrel with them Viet Cong" was perhaps one of the more telling remarks of the era.

In the Ring Again. He was allowed to return to boxing in 1970; in 1971 the Supreme Court ruled that the government had acted improperly. In 1974, he fought George Foreman in Zaire. During that fight, which was dubbed "The Rumble in the Jungle," he regained the heavyweight title. Ali went on to defend it against an intense 15-round match with Joe Frazier in the Philippines the next year. He lost the title in 1978 to Leon Spinks but later defeated Spinks in a rematch.