Demetrious Johnson turned pro in 2009 and after 15 long years, he finally announced his retirement from MMA during ONE 168: Denver. The former UFC flyweight champ has 12 title fight wins and boasts one of the longest win streaks (13) in the promotion.
During his illustrious UFC run, Johnson walked through the flyweight division with ease. Although his one-sided beat downs didn't gather a ton of PPVs, he's now regarded as one of the best fighters of all time.
