UFC 137 Results: The Best And Worst Of B.J. Penn On Display In Loss To Nick Diaz

If that was the final time we get to see B.J. Penn perform in the Octagon, at least we got a glimpse of the great fighter at his best and his worst. Penn is one of the sport's great enigmas - and tonight was no exception. Eyeballs don't lie. Mine tell me Penn was overweight and probably a little out of shape. The spare tire around the middle was living proof. So were the heaving breaths after less than two rounds of action.

That's come to be a tradition for Penn, especially when he makes the journey up to 170 pounds. But the extra weight and fitness issues weren't the whole story. They never are for Penn, a fighter with so many natural gifts. In the first round he's still one of the best of all time. He beat Nick Diaz to the punch, busting his face up and making him miss. He also scored a takedown and outgrappled the grappling wizard. He looked, in short, like B.J. Penn.

The longer the fight went the more he looked like B.J. Penn - the other B.J. Penn, the evil doppelganger who likes the beach and the dinner table a little too much. The one who faded against Frankie Edgar. The one who could barely continue against Jon Fitch. The one who lost winnable fights against both Georges St. Pierre and Matt Hughes.

For Diaz, it's sweet, sweet vindication. There can be no more whispers that he doesn't belong with the UFC's best. He beat Penn, not just winning on scorecards, but battering him in a way we've rarely seen the great ones manhandled. When he challenged Georges St. Pierre, suddenly it seemed like more than just vanity. Look closely and you'll see a glimmer of doubt in St. Pierre's eye when the camera cuts to him cageside. Nick Diaz will do that to a man.

If this is indeed Penn's last fight, it's fitting that he passes the torch to Diaz. The two are similar in approach; Diaz is like an especially angry Penn, one who can't maintain the composure it's taken Penn years to develop. That's the circle of life in combat sports. It's a young man's game, one that demands a fighter be at his best both mentally and physically. If not, the consequences can be devastating.

If Penn has the inkling it's time to call it quits, it probably is. The cage is no place for the halfhearted or the unsure. Penn has given plenty of blood and sweat, chills and moments we will never forget. Diaz can step into his niche, try to fill his gigantic shoes. It will be fun to watch him try.