UFC 158 on Saturday is headlined by the on-again off-again Welterweight Championship fight between Nick Diaz and champion Georges St-Pierre. The fight, originally scheduled for UFC 137 in October of 2011 was canceled because Diaz missed several press appearances for the UFC. Carlos Condit was given the title fight (which GSP missed due to an injury) and Diaz defeated BJ Penn in what was the new main event. After the fight, Diaz called out GSP, which made the French-Canadian furious and demanded Dana White give him the next shot in February of 2012. St-Pierre's injury was worse than expected and he had to drop out of that fight as well.
Diaz and Carlos Condit fought for the Interim Welterweight belt at UFC 143 on that show instead. Diaz lost a controversial decision, and threatened to retire in his post-fight interview. It was later announced that Diaz tested positive for marijuana and would be suspended for 12 months. GSP made his comeback and beat Carlos Condit at UFC 154 in October. GSP requested that his next title defense would be against Nick Diaz, and here we are.
UFC 158 features 4 of the top 5 Welterweights in the company, and the immediate future of the division will be determined by the top 2 fights. All four of these men have a lot to gain and/or lose on Saturday.
1) Georges St-Pierre
GSP is entering this event on a ten-fight (almost six year) winning streak, since being upset by Matt Serra in 2007 (at one point he won 33 straight rounds, which is unheard of). Along with Anderson Silva and Jon Jones, you can make a case that he is the best pound-for-pound fighter in the sport. A win against Diaz will further cement his legacy as the best ever, and possibly set up a super-fight that has been rumored for years between him and Silva. GSP has shown a more ruthless side of his personality in the build to this fight, at one point calling Diaz "an uneducated fool" and saying "he's the most disrespectful human being I've ever met and I'm going to put the worst beating on him you've ever seen in the UFC". A lot of pundits are questioning if Diaz was successful in getting into the Champ's head.
2) Nick Diaz
The person who eventually unseats GSP as Welterweight Champion will immediately have a huge mark on his resume. Diaz may pose the biggest threat out of any opponent that St-Pierre has faced. He is a dangerous striker and Jiu-Jitsu black belt. GSP will be able to take him down and out-wrestle him, but he must be aware of Diaz, who is great at getting submissions on his back. With all the fame, glory, and money to be gained if he wins, Diaz could possibly cost himself his UFC career with a loss. It's no secret that Dana White doesn't get along with the brothers from the "209", and the only reason White has put up with Diaz's antics was because he knows he can make a ton of money off of this fight. If Nick loses he will certainly have 2 strikes against him and a future slip-up could be costly.
3) Johny Hendricks
Hendricks, who was originally scheduled to face Jake Ellenberger, but after an injury to Rory MacDonald, is going to fight Carlos Condit instead. Hendricks feels like he should be the number one contender to GSP's belt after knocking out Jon Fitch and Martin Kampmann in the first round of their fights. With a win on Saturday, against the former #1 Contender will almost guarantee that Hendricks gets his wish for a date with St-Pierre. Condit is a dangerous fighter in his own right, and has one-punch knockout power as well. A loss will knock Hendricks down a couple pegs and he will have to be patient for a potential title fight.
4) Carlos Condit
"The Natural Born Killer" is looking to get back in contention after a war with St-Pierre in October. Condit is in a strange position, because the last person who had a title rematch against GSP was BJ Penn in 2009, and usually after a loss to St-Pierre, a lot of fighters never reach the top again (Koscheck, Dan Hardy, Thiago Alves, Jake Shields for example). Condit's original opponent, Rory MacDonald made more sense, since Rory doesn't want to fight his training partner GSP, thus a loss by either fighter won't hurt a potential #1 contender.