UFC 79: Nemesis was a mixed martial arts (MMA) event held by the Ultimate Fighting Championship (UFC), that took place on December 29, 2007, at the Mandalay Bay Events Center in Las Vegas, Nevada.

[2] The main events featured the fight between Chuck Liddell and Wanderlei Silva,[3] as well as the rubber match between former UFC Welterweight Champions Georges St-Pierre and Matt Hughes for the interim Welterweight championship.

[4] Additionally, Pride Light Heavyweight Rameau Thierry Sokoudjou made his UFC debut against undefeated Lyoto Machida.

[5] The main event was originally scheduled to have The Ultimate Fighter 6 coaches Matt Serra and Matt Hughes for Serra's UFC Welterweight Championship, which Serra won at UFC 69: Shootout on April 7, 2007, in an upset victory over Georges St-Pierre.

[2] Serra, however, withdrew from the fight due to a back injury,[6] Serra was replaced by St-Pierre, though the fight would now be contested for the interim Welterweight Championship, with the winner facing Serra afterwards.