Despite Diaz's win streak, Penn was still a significant step up in competition for the Cesar Gracie pupil. Diaz, however, rose to the challenge in what become an absolute brawl for three rounds. In the process, Diaz showcased his tendency to put on exciting fights as well as his excellent boxing ability.
While Georges St-Pierre will easily be the toughest challenge of his career, let's take a look at why Nick Diaz could possibly be the next UFC Welterweight Champion.
One of the biggest reasons why Nick Diaz was successful in his bout with BJ Penn was his unbelievable stamina.
Despite losing the first round, Diaz was clearly the fresher fighter in both rounds two and three, maintaining his relentless pace for fifteen minutes and overwhelming "The Prodigy."
Diaz, who frequently competes in triathlons, has shown his ability to fight hard for five rounds before and considering the kind of fighter Georges St-Pierre is, it's very likely he'll have to again.
While every title challenger proclaims their intention to "take the fight to Georges St-Pierre," most allow him to set the pace and ultimately become victims to his game plan.
Diaz, particularly with his sizable gas tank, will not hesitate to be extremely aggressive and push the pace. While St-Pierre always enters his fights in amazing shape, it's unlikely he'll have ever fought at a pace that Diaz will push him to fight at.
Nick Diaz doesn't really care what anyone thinks of him and has no problem "playing the bad guy to get a fight." As a result, he seems to have already gotten under the skin of Georges St-Pierre who has called him "the most disrespectful person [he has] ever met."
Whether it is before the fight or during, Diaz has an uncanny way of turning fights into brawls and making his opponents throw their game plans out the window.
Diaz frequently threw his hands up in the air or dropped them down to his sides while leaning his head forward in order to taunt BJ Penn at UFC 137. His distracting tactics make him a very difficult opponent to deal with.
While Josh Koscheck's intention to play mind games with St-Pierre proved fruitless, he is not quite on the same level as Nick Diaz.
While Nick Diaz has developed his hands in recent years, he has always been an amazing Jiu-Jitsu fighter under the tutelage of Cesar Gracie. In a world where it seems like nearly every mixed martial artist has a black belt, a black belt from Gracie means a great deal.
Diaz has one of the craftiest ground games in the division and if Georges St-Pierre can put him on his back, he'll constantly have to be aware of submission attempts.
Many finally became aware of Diaz's unorthodox guard after his gogoplata of Takanori Gomi at Pride 33.
While Diaz doesn't have very strong wrestling skills, he has been able to rely on his excellent Brazilian Jiu-Jitsu whenever the fight does hit the ground. He won't want to spend too much time with St-Pierre on top of him, but he certainly won't be out of his element if it happens.
BJ Penn was able to control Diaz on the ground in the first round, but it was a very short period before he got back to his feet.
In his last four fights, Diaz has taken out several great strikers in KJ Noons, Evangelista Santos, Paul Daley, and BJ Penn.
Diaz has shown that he has some of the best boxing in the sport. Georges St-Pierre doesn't have the same "one-punch knockout power" to worry about as he did with Josh Koscheck, Thiago Alves and Dan Hardy, but he will have to concern himself with constant strikes.
Even BJ Penn's unbelievable chin was in trouble against Diaz.
It's very possible that GSP will bring the fight to the ground whenever he's in trouble on his feet, but if he can't, it will be a very interesting fight.