He was best known for his 12-round victory over Muhammad Ali, when he famously broke Ali's jaw, on March 31, 1973, becoming only the second man to defeat a peak Ali as a professional (after Joe Frazier, who won a 15-round unanimous decision against Ali on March 8, 1971).
- Goldstein, Richard (September 18, 2013). "Ken Norton, a Championship Fighter Who Broke Ali's Jaw, Is Dead at 70". New York Times.
- "Ken Norton, heavyweight boxing legend, dies at 70". BBC. 19 September 2013. Retrieved 19 September 2013.