UFC 100: Brock Lesnar vs Frank Mir UFC Picks: The newest and biggest UFC star, both figuratively and literally, Brock Lesnar, will defend his heavyweight title belt Saturday night against Frank Mir. The Brock Lesnar vs. Frank Mir fight will be a rematch from their first encounter 17 months ago when Mir, 12-3, almost broke Lesnar’s leg in the 1st round. Lesnar, 3-1, is a 6’3” 265 Lb. hulking presence that is angry and ready to repay Mir with his own dose of pain. Despite Mir’s submission win in the first fight money has poured in on Lesnar with the bookies.