Few gave Norton much of a chance in the 1973 non-title fight against Ali in San Diego, but his awkward style and close-in pressing tactics confused the former champion, who fought in pain after Norton broke his jaw in the early rounds. He won by split decision.
The loss was even more shocking because Ali had only lost to Joe Frazier in their 1971 showdown and was campaigning for the title he would win again the next year against George Foreman in Zaire.