Ultimate Fighting Championship returned to pay-per-view last Saturday night with UFC 137: "Penn vs. Diaz," featuring former Strikeforce champion Nick Diaz staking his claim to the title shot that was always his by beating up B.J. Penn for 15-minutes strong.

Nick Diaz overwhelms B.J. Penn in the main event of UFC 137 tonight (Oct. 29, 2011) in Las Vegas, Nevada, to earn a hard-fought, bloody unanimous decision victory. The Stockton slugger used his superior cardiovascular conditioning and never-say-die attitude to blast his way past "The Prodigy," who was undoubtedly the toughest match-up to date for Diaz.

Destined to be in the UFC Hall of Fame, BJ Penn went toe-to-toe with former Strikeforce champion Nick Diaz. In the end, it was the well-versed Cesar Gracie fighter who proved to be too much for the Hawaiian.

In the early goings, Penn, also known as The Prodigy, found some success in taking Diaz to the mat. However, the equally dangerous submission specialist was able to negate any forthcoming attacks.

On the feet, though, it was all Diaz. The Stockton native proved just how dangerous he is, outgunning Penn time and time on the feet. Diaz continued digging the former two-time champ with shots to the head and the body throughout the fight.

Diaz won a clear cut decision victory over the legendary fighter, laying the ground for a possible bout with the current welterweight kingpin in Georges St-Pierre.

Preliminary Bouts (Spike TV)

Tyson Griffin defeated Bart Palaszewski

Dennis Siver defeated Donald Cerrone

Clifford Starks defeated Dustin Jacoby

Chris Camozzi defeated Francis Carmont

Ramsey Nijem defeated Danny Downes

Brandon Vera defeated Eliot Marshall

Main Card

Hatsu Hioki defeated George Roop

Scott Jorgensen defeated Jeff Curran

Roy Nelson defeated Mirko Cro Cop Filipovic

Cheick Kongo defeated Matt Mitrione

Nick Diaz defeated BJ Penn

GSP injured; Penn-Diaz Elevated to 137 Main Event

Returning UFC welterweight contender Nick Diaz will get his UFC 137 main event after all, as UFC President Dana White announced via twitter Tuesday afternoon that 170-pound champion Georges St-Pierre has been forced to withdraw from his October 29th title defense against Carlos Condit due to a knee injury.