Feb. 25, 1964: Sonny Liston, left, fights Cassius Clay for the world heavyweight title in Miami Beach, Fla. Just three of 46 sports writers covering the fight at Convention Hall reportedly picked Clay to win. (Ralph Morse—The LIFE Picture Collection/Getty Images)
Feb. 25, 1964: Clay, of Louisville, Ky., had an impressive professional record of 19-0 entering the bout, but many in the boxing world expected "Big Bear" Liston to handle the "Louisville Lip" with relative ease. (Ralph Morse—The LIFE Picture Collection/Getty Images)
Feb. 25, 1964: Clay's rare mix of speed, footwork and power overwhelmed Liston from the start, as the champion's typically lethal left hook could not catch the brash challenger. (Ralph Morse—The LIFE Picture Collection/Getty Images)
Feb. 25, 1964: Liston's manager later said that the former champion injured his left shoulder during training, The Associated Press reported. Asked why the Liston camp didn't postpone the fight, manager Jack Nilon said: "We thought we could get away with it." (Ralph Morse—The LIFE Picture Collection/Getty Images)
Feb. 25, 1964: Clay, upon being announced as the world's new heavyweight champ, told a throng of reporters: "Eat your words." Earlier, he shared several lines of poetry leading up to the fight, including: "The crowd did not dream when they put up the money / that they would see a total eclipse of the Sonny." (Ralph Morse—The LIFE Picture Collection/Getty Images)
Feb. 25, 1964: Clay and Liston met as the nation was on the eve of massive change. Still deep in mourning over the assassination of President John F. Kennedy just three months earlier, the country would be rocked by race riots in major cities in the long, hot summer ahead. Civil rights activism was gearing up, the conflict in Vietnam was moving into U.S. headlines. (AP)