Muhammad Ali successfully defended the heavyweight title 10 times during his second reign, from 1974 to 1978.
Ali began this reign by defeating George Foreman by eighth-round knockout in the “Rumble in the Jungle” on October 30, 1974. The victory restored Ali as the undisputed heavyweight champion nearly seven years after he had been stripped of his title and suspended from boxing for refusing induction into the U.S. Army.
His 10 successful defenses included major victories over Joe Frazier in the “Thrilla in Manila,” Ken Norton, Ron Lyle, and Earnie Shavers. Several defenses went the full 15 rounds, reflecting the demanding championship format of that era. Ali finally lost the title to Leon Spinks by split decision on February 15, 1978.
The number can be confused with Ali’s career total. He made 19 successful heavyweight title defenses across his first two major reigns: nine during his initial reign and 10 during this second one. His later 1978 victory over Spinks began a third title reign, rather than adding to the second.