On April 10th 2010 Frankie Edgar pulled out a decision win against Bj Penn to become the 4th UFC lightweight champion. He beat him again at UFC 118 only four months later and in a rematch. At UFC 125:Resolution his second fight with Gray Maynard went to a draw.
Frankie was set to fight Maynard again on memorial day weekend at UFC 130 at the MGM in Las Vegas Nevada, U.S.A but both fighters had to pull out because of injury. He faced Gray Maynard on October 8th in Houston Texas at UFC 136. The fight went similar to their second except Frankie won by TKO in the fourth round. He ended the trilogy with the belt. At UFC 144 in Tokyo Japan in the Saitama Super Arena edgar lost a decision to Benson "Smooth" Henderson. The fight was controversial enough to some people to warrant a rematch that is rumored to happen at UFC 150