Earnie Shavers was one of the most terrifying punchers in heavyweight boxing history. To put things into perspective, Ken Norton, the man who continuously gave “The Greatest” trouble, fell to Shavers in one round. While not the most polished boxer, Shavers had pure dynamite in his gloves and getting hit by him would surely solve even the strongest case of insomnia.

Muhammad Ali battled Shavers in a brutal 15-round contest. Although he was able to earn a unanimous decision, the champion was forced to eat brutal blow after brutal blow. Simply put, Shavers pulled Ali into a grueling nightmare. After the bout, Ali was always candid about Shavers and his punching power: “Next to Joe Frazier, that was the hardest I ever got hit” (via “Facing Ali”). While not possessing the most scientific fighting style, Shavers was still able to predict some of Ali’s pattern of attack, finding opportunities to counter the champion’s signature right hand. However, Ali, forever the crafty veteran, was able to hide being hurt and would jokingly wobble his legs whenever Shavers landed something good. “Ali was a very, very smart fighter. He knew how to con you in many different ways,” Shavers admitted in the “Facing Ali” documentary.

In the end, Ali pulled out another close victory. He always tried to end every round strong in order to leave an impression on the judges, and in the last round, despite being put through 14 rounds of agony, the champion came out and put on a hellacious pace, staggering Shavers with crisp rights and lefts. With his triumph over Shavers, Ali once again proved to be one of the most resilient boxers in the history of the sport.