1973: Norton Upsets Ali

On This Day in Sports: March 31, 1973

On March 31, 1973, Ken Norton defeated Muhammad Ali by split decision in a twelve-round heavyweight bout in San Diego. Norton entered as a significant underdog without a championship résumé, while Ali was pursuing another path toward the title after his first loss to Joe Frazier. The result disrupted those expectations and introduced a difficult stylistic rival who would challenge Ali across three closely contested fights.

Norton used a high crossed-arm guard, steady pressure and a stiff jab to interrupt Ali’s rhythm. Rather than following Ali around the ring, he stepped into punching range and made the faster fighter work through physical exchanges. Ali sustained a broken jaw during the bout but continued to the final bell. The injury emphasized his endurance, yet the judges awarded Norton the narrow decision he had earned.

The upset immediately changed both careers. Norton gained recognition as a leading heavyweight and received a lucrative rematch less than six months later. Ali won that second contest by split decision, again showing how little separated them. Their third meeting came in 1976 at Yankee Stadium, where Ali retained the heavyweight championship through another disputed and intensely debated decision.

Norton’s victory remains an example of preparation overcoming reputation. He did not try to imitate Ali’s movement or compete only at long range; he imposed a guard, pace and angle that made the favorite uncomfortable. The March result turned one upset into a trilogy and secured Norton’s place in heavyweight history, while adding another demanding chapter to Ali’s long return toward the championship. The upset still commands respect today.