LAS VEGAS - UFC welterweight champion Georges St-Pierre will meet Strikeforce title-holder Nick Diaz in October.

The mixed martial arts fight is set for UFC 137 on Oct. 29 at the Mandalay Bay Events Center in Las Vegas.

"U wanted it! U GOT IT!!!" tweeted UFC president Dana White.

St-Pierre (22-2) is coming off a decision win over Jake Shields at UFC 129 in Toronto. The 30-year-old from Montreal has defended his 170-pound title six times since winning it back from Matt Serra at UFC 83 in April 2008.

Like St-Pierre, Diaz (14-6) has not lost since 2007. The 27-year-old stopped Paul (Semtex) Daley in the first round last time out in Strikeforce.