UFC President Dana White credits Penn with bringing the lower weight divisions into the mainstream of mixed martial arts. Penn is the second of seven fighters in UFC history to win titles in multiple weight classes. Penn unofficially unified the UFC Lightweight Championship (against Sean Sherk) and broke the all-time lightweight title defense record.
See also: B. J. Penn (United States Navy), Georges St-Pierre, Matt Hughes (fighter), List of UFC champions, Malki Kawa, and The Ultimate Fighter 5.