Brock Lesnar

Brock Lesnar is one of the most improbable champions in UFC history. A pro-wrestling superstar and NCAA Division I wrestling champion, he stepped into MMA and won the UFC Heavyweight Championship in only his fourth professional fight, dethroning the legendary Randy Couture in 2008. His arrival brought a wave of new, mainstream attention and made him one of the biggest pay-per-view draws the sport has known.

In the cage, Lesnar was a physical anomaly: a 265-pound athlete with explosive quickness and smothering wrestling who buried opponents under his size and ground-and-pound. He avenged his only loss by dominating Frank Mir at UFC 100, one of the most-watched events in company history, and defended his belt before a serious bout of diverticulitis derailed his momentum.

The rise of a new generation caught up with him, as Cain Velasquez and Alistair Overeem exposed the gaps in a still-developing skill set. Lesnar retired with a modest 5-3 record and a no-contest, and his story remains a debate: a polarizing figure whose star power and athletic gifts were undeniable, even as critics argued his fame opened doors his fight resume alone never would have.