Middleweights Chris Leben and Derek Brunson faced off to start the UFC 155 PPV show. Brunson opened up the action with a blocked head kick. Leben caught a kick, but got picked up in the clinch and put on his back. Leben was active from his back, looking for the armbar and escapes. Brunson got mount, but Leben worked back to half guard. Leben got to his feet by the end, but didn't get anything offensive going.

Brunson looked tired after the first, but still went for a takedown early in the second. Defended by Leben. Leben with a big left hook, but gave up the takedown. Back on the feet Leben landed a big uppercut.. Brunson was exhausted halfway through the round. Leben kept trying to walk him down, but the bigger man did well staying out of range.

Leben defended an early takedown from Brunson, but gave up the trip on the second attempt. Back on the feet and both guys were tired. Leben walked Brunson down but had a lot of trouble landing shots. Ugly striking from both before Brunson scored another takedown in the last minute.

Derek Brunson got the unanimous decision (29-28 x 3) over Chris Leben.