Georges St-Pierre asked for the fight, and Nick Diaz agreed to the match. Now, it's finally happening.
GSP will headline the card with his 10th consecutive welterweight title match, this time against against top contender Diaz at UFC 158 in Montreal, giving the champion the home-country advantage.
"Georges St-Pierre asked to fight Nick Diaz because he knows they have unfinished business, and Nick Diaz agrees," UFC president Dana White said, according to the UFC's news release.
Diaz's title shot comes with no small amount of controversy, as the former Strikeforce welterweight champion is coming off his first loss after an 11-fight, three-year winning streak. Former interim UFC champion Carlos Condit handed Diaz the loss via decision but was later defeated by St-Pierre after a bloody five-round brawl at UFC 154 last November.
Diaz is also expected to obtain his fighter's license before competing in Canada, as he's currently serving a suspension on a positive drug test for marijuana metabolites following his UFC 143 fight with Condit.
Tickets for the event, held at Montreal's Bell Centre, will be for sale online starting on Jan. 19.
UFC 158 is expected to be the promotion's first event in Canada and fourth international card for 2013, while also being its third pay-per-view event of the year behind UFC 156 (Jose Aldo vs. Frankie Edgar) and UFC 157 (Ronda Rousey vs. Liz Carmouche).