Ken Norton vs. Muhammad Ali II, billed as Battle of the Broken Jaw, was a professional boxing match contested on September 10, 1973, for the NABF heavyweight championship.

Norton weighed in at 206 lbs (5 pounds lighter than his first match with Ali) and leading to some boxing writers suggesting that his preparation was perhaps too intense and that he may had overtrained.

However, Ali demonstrated his physical stamina by skipping without pause and standing between rounds.

Norton came out aggressively in the beginning of the fifth round, leading with a barrage of jabs and pushing Ali to a more defensive posture.

Though the match was close, Ali ended up winning the split decision with Dick Young scoring it 7-5 and John Thomas 6-5 with George Latka having for Norton 6-5.