In the post fight interview with Joe Rogan, Penn said that he is ready to retire. Penn told Rogan "Hats off to Nick Diaz. He's the man. Joe, this was probably the last time you'll see me in here. I can't keep performing at the top level. That's it Joe. I got a daughter and another daughter on the way, I don't want to go home looking like this. I'm done."
Penn remains one of only two men, along with Randy Couture, to win UFC titles in multiple weight classes. Penn made his professional MMA debut at UFC 31 and became one of the sport's biggest stars, capturing the welterweight title from Matt Hughes in a shocking fight at UFC 46. He would never actually lose that title, instead leaving the UFC for two years. At UFC 80 he captured the UFC lightweight title with a win over Joe Stevenson, a title he would defend three times before losing it to Frankie Edgar.
After tonight, Penn had only won one of his previous five bouts and decided it was time to step away from the sport.
Bloody Elbow will have much more on the card and the great career of B.J. Pen in the coming days.
SBN coverage of UFC 137 Results: Penn vs. Diaz