UFC 137 Fight Card: Nick Diaz Will Punish B.J. Penn in Return to UFC

Tonight's main event on the UFC 137 fight card may not draw the same attention as some of the more recent fights, but it will surely be one of the more entertaining.

The original main event for this evening was scheduled to be Georges St-Pierre defending his title against Carlos Condit, but the fight was canceled due to a knee injury sustained by St-Pierre.

Instead, Nick Diaz (25-7) makes his return to the UFC tonight after completely dominating the competition in Strikeforce.

Diaz has greatly evolved as a fighter since his original run in the UFC. In fact, his aggressive style has him undefeated in the ring since November 2007.

He looks to keep that streak alive tonight in his fight against B.J. Penn (16-7).

Penn was the UFC lightweight champion for nearly two-and-a-half years before losing the title to Frankie Edgar last year.

Penn is known much more for his success in the lightweight division. Tonight's scheduled fight is a welterweight title eliminator.

Over the years, many have questioned Penn's dedication and commitment in the ring. He has looked sloppy and careless at times, resulting in many of his losses.

If that's the case tonight, then Diaz should face little resistance.

Both Penn and Diaz are extremely difficult to finish. Neither has ever lost a bout via submission. Each have only been knocked out twice.

Interestingly enough, both rely on knockouts and submissions to get victories. Both have losing records when the fight goes to a decision.

This match is going to consist of two guys standing toe to toe and slugging it out. The advantage clearly goes to Diaz in this category.

The two are actually very similar in ability, but Diaz brings an angry attitude and forceful essence in the ring.

It's that attitude that will give him the upper hand tonight.