A Notorious Legacy: 5 Moments That Defined Conor McGregor’s Career

5. "The Money Fight"

While McGregor made a name for himself in the UFC, his most lucrative fight actually took place inside a boxing ring. In fact, more people watched McGregor versus Mayweather than any of his UFC fights. The matchup did around 4.3 million pay-per-view buys —making the 2nd most successful event in combat sport's history.

McGregor would end up losing the fight via TKO in the 10th round. However, the notoriety he received for his involvement, made him a household name. When he signed the bout agreement to fight Mayweather, McGregor went from being the biggest draw in MMA to one of the biggest stars in all of sports.

"The Money Fight" is hands down the most successful event a professional mixed martial artist has ever been a part of — both financially and in terms of viewership.