The following are the official results from UFC 91:

Brock Lesnar Wins by Technical Knock Out at 3:07 in the 2nd round.
Kenny Florian Wins by Submission (Choke) at 4:03 in the 1st round by rear naked.
Gabriel Gonzaga Wins by Technical Knock Out at 1:01 in the 1st round .
Demian Maia Wins by Submission (Choke) at 2:13 in the 1st round by rear naked.
Dustin Hazelett Wins by Submission (Arm Lock) at 3:59 in the 1st round by arm bar.
Aaron Riley Wins by Unanimous Decision at 5:00 in the 3rd round .
Jeremy Stephens Wins by Technical Knock Out at 0:39 in the 3rd round .
Mark Bocek Wins by Submission (Choke) at 3:16 in the 3rd round by rear naked.
Matt Brown Wins by Submission (Arm Lock) at 0:57 in the 2nd round by arm bar.