UFC Fight Night 15: Diaz vs. Neer was a mixed martial arts event held by the Ultimate Fighting Championship (UFC) on September 17, 2008, at the Omaha Civic Auditorium in Omaha, Nebraska.

UFC 83: Serra vs St-Pierre 2 was a mixed martial arts event held by the Ultimate Fighting Championship. The event was held on April 19, 2008, at the Bell Centre in Montreal, Quebec, Canada. UFC 83 was the UFC's first event in Canada. It was headlined by UFC Welterweight Champion Matt Serra and UFC Interim Welterweight Champion Georges St. Pierre in a match to unify the championship.