Mr. Norton was a gifted all-around athlete who didn’t turn to boxing until he was serving in the Marine Corps in his 20s. Before he faced Ali in San Diego on March 31, 1973, he had been a lightly regarded journeyman who had fought few top-notch opponents. He was a single father raising a son on his own and made only $300 for his previous fight, which was held before a crowd of 700.
For his fight with Ali, he accepted $50,000 for a 12-round fight to be broadcast on national television. It was expected to be an easy romp for Ali, who was angling for a title shot against then-champion George Foreman.
The 6-foot-3, 210-pound Mr. Norton was a 5-to-1 underdog, but he was in superb condition and proved to be a formidable force in the ring.
“He had a body-builder’s physique, with arms that appeared ready to pop, the legs of a middleweight, a 44-inch chest and a 31-inch waist,” Sports Illustrated reported at the time. “No fighter Ali has met, save [Joe] Frazier” — the only boxer who had previously beaten Ali — “seemed less intimidated.”
Mr. Norton had an unorthodox style, with his arms often crossed in front of his body, that seemed to confuse Ali. In the second round, he caught Ali along the ropes and delivered a right uppercut. Most experts believe Ali’s jaw was broken with that punch, but he battled on gamely for 10 more rounds.
Mr. Norton won the fight by a split decision and immediately entered the front rank as one of the country’s leading heavyweights. It was only the second time Ali had lost in his professional career.
Before the fight, TV commentator Howard Cosell said it was one of the worst mismatches he had ever seen. Afterward, Cosell apologized, saying, “Kenny, you made me look silly.”
“That’s okay, Howard,” Mr. Norton replied. “You always look silly.”
Six months later, Mr. Norton narrowly lost a rematch to Ali, who went on to reclaim the heavyweight championship from Foreman in 1974. Mr. Norton met Ali for a third time on Sept. 28, 1976, at New York’s Yankee Stadium.
At the beginning of the 15th and final round, Mr. Norton believed he was ahead on points and would win the title if he could avoid being knocked out. Ali pressed forward during the round, as Mr. Norton waited until the final seconds to launch a counterattack. It came too late, as the judges awarded the fight to Ali in a close but unanimous decision.
“I look back and wish I could fight that last round over again,” Mr. Norton told Thomas Hauser for the 1991 oral biography “Muhammad Ali: His Life and Times.” “I won that fight . . . I’m getting mad again, talking about it. But Muhammad brought out the best in me. He was the best fighter I ever fought, and I respect him.”