On this day in 1978, Leon Spinks upset the great Muhammad Ali.

‘The Greatest’ headed into the bout after defeating the hard-hitting Earnie Shavers a year prior. Spinks, meanwhile, was a former Olympic gold medalist in 1976. He went pro a year later and had an undefeated 7-0-1 record heading into his showdown with Ali.

While ‘Neon’ was unbeaten in his professional career, none of his previous fights indicated he would fare well in his bid for heavyweight gold. Oddsmakers had the Olympian as a 10-1 underdog heading into his fight with the WBA, WBC and The Ring Heavyweight Champion.

However, Spinks was able to upset the odds that night in Las Vegas. ‘Neon’ was one step ahead of his older foe the entire bout and was the more active fighter down the stretch. Going into the 15th round, Ali knew he needed a finish and he gave fans one of the wildest rounds in heavyweight history.

‘The Greatest’ came out swinging to retain his title, landing multiple big flurries. Spinks fired back with some punches of his own and was able to back up the future Hall of Famer enough to see the judges scorecard. At the end of the bout, ‘Neon’ became the Heavyweight Champion, winning via decision.

The bout was named The Ring‘s ‘Fight of the Year’ for 1978. Furthermore, round 15 was named The Ring‘s ‘Round of the Year’ as well.

Leon Spinks lost the rematch to Muhammad Ali later that year

Despite speculation that Muhammad Ali would retire following his loss to Leon Spinks, ‘The Greatest’ decided that he couldn’t go out on that note. In September 1978, the two future Hall of Famers squared off once again.

The odds for the fight were much closer this time around. Many expected the 36-year-old Ali to be able to regain his crown. This time, ‘The Greatest’ lived up to his nickname. He regained the WBA and The Ring Heavyweight titles.

The rematch wasn’t nearly as entertaining as the first encounter, mainly due to a different gameplan from the former champion. Realizing that he likely wouldn’t be able to outwork a boxer a decade younger than him, he slowed down the fight.

Ali worked his jab to perfection and anytime the Champion tried to fire anything off, he clinched him. It wasn’t pretty, but at the end of 15 rounds, ‘The Greatest’ was once again the Heavyweight Champion for the third time.