The top welterweights in the world converge on the Bell Centre in Montreal on Saturday, March 16th, for an unforgettable night of fights. Before the event, catch an all-new Countdown to UFC 158. In the main event, welterweight champion Georges St-Pierre (23-2 MMA, 17-2 UFC) faces his fiercest rival, Nick Diaz (26-8 MMA, 7-5 UFC), in an anticipated showdown. Plus, another rivalry is born when "The Natural Born Killer" Carlos Condit (28-6 MMA, 5-2 UFC) meets 170-pound knockout artist Johny "Big Rigg" Hendricks (14-1 MMA, 9-1 UFC). Then Jake "The Juggernaut" Ellenberger (28-6 MMA, 7-2 UFC) goes toe-to-toe against Nate "The Great" Marquardt (32-11-2 MMA, 10-4 UFC).