The fight was for the UFC interim heavyweight championship, with Antonio Rodrigo Nogueira defending. The two men had been coaches together on the eighth season of The Ultimate Fighter reality show. The winner of the fight would face off against new heavyweight champion Brock Lesnar to unite the two titles. Nogueira was a heavy favorite coming into the fight, but it was not common knowledge that he was heavily afflicted with a bad case of staph infection at the time.
The fighters came out without touching gloves and began circling. Mir began dominating the striking with his improved boxing. Mir took Nogueira down and began ground-and-pounding him. Mir allowed Nogueira to stand. The striking once again resumed. Mir dropped Nogueira with a strike but once again allowed him to stand. The striking resumed. Nogueira put together a nice combination, but Mir was smiling. He knew what the outcome of the fight would be at that point. Mir dropped Nogueira for the second time at the end of the first round and went to his corner looking very calm. Nogueira seemed frustrated.
The second round began and the fighters came out. Mir once again began dominating the striking game. Mir dropped Nogueira for the third time of the fight with three minutes and fourteen seconds left in the second round. Mir somehow knew this was the time to finish and he began viciously ground-and-pounding. Herb Dean almost immediately stopped the fight and Frank Mir was the new interim heavyweight champion. Nogueira was finished for the first time in his career. Nogueira and Mir were both very emotional after the fight. Mir stated that he had 'never been more afraid in my life than I was when I walked into that cage.'