
21. Lennox Lewis (2001)
Preparation is essential in the sport of boxing. Fighters have to maintain total focus inside and outside of the ring. Somebody forgot to tell Lewis this before his bout with Hasim Rahman in South Africa. The pair fought in a small mining town called Brakpan at a high altitude. Rahman arrived a month before the fight so that his body could adjust. But Lewis prepared in a different manner.

He chose to train in Las Vegas so that he could shoot his scenes for Oceans Eleven at the same time. This was a fatal decision because he wasn’t ready for Rahman. Lewis expected to fight Mike Tyson and didn’t treat Rahman with the same seriousness. But he lost in one of boxing’s most shocking defeats. Rahman beat him by knockout in round five. It was Lewis’s fault for taking his abilities for granted.