Barnett came out swinging, Mir was able to respond in kind, but it was clear both man had bad intentions. Barnett pinned him up against the fence and the pair exchanged some dirty boxing, with "Baby-faced Assassin" getting the better of the mixed martial arts (MMA) action.
He looked like he was angling for a standing choke during a rare lull in the action, but then he delivered a knee to Mir's grill that made him do an immediate face plant. He seemed like he was out, with Barnett ready to go for the kill, before the referee stopped him from dishing out additional punishment.
Mir sprung to his feet in protest, suggesting it was a premature stoppage. He seemed like he had his wits about him, but it was too late, he now has three straight losses (Junior dos Santos Daniel Cormier are the other two), while Barnett nets his first UFC win since 2002.
Likely not his last, perhaps even over Mir, who undoubtedly will lobby for a rematch based on the controversial call.
For complete UFC 164: "Henderson vs. Pettis 2" results, including play-by-play coverage of the entire PPV event, click here.