The Heavyweight Championship of the World: Cassius Clay versus Sonny Liston (1964) (movie): This was the first heavyweight title fight between Cassius Clay (aka Muhammad Ali) and Sonny Liston. Clay won the fight by technical knockout (TKO) after six rounds, when Liston failed to answer the bell for the seventh round. Discover the latest Discussions, Reviews, Quotes, Theories, Explanations and Analysis of The Heavyweight Championship of the World: Cassius Clay versus Sonny Liston (1964) below