This was dos Santos' first title defense since winning the belt from Cain Velasquez in November. He came into the fight with a record of 14-1, while Mir held a record of 16-5.
Mir went for a takedown right away, but true to form, dos Santos was able to step out of the attempt. The two men stood and traded for the rest of the round. With about 20 seconds remaining in the round, dos Santos absolutely unloaded with a flurry of blows that appeared to knock Mir out on his feet. Somehow, Mir survived to the bell.
Dos Santos knocked down Mir right away in the second round, but Mir recovered and got back to his feet. The challenger was not quite as lucky as he was knocked down again with just under two minutes remaining and we clearly loopy. dos Santos landed one more blow for good measure as the fight was waved off, awarding dos Santos the victory via TKO at 3:04 of the first round.
Here are the full results from UFC 146:
Heavyweight bout: Cain Velasquez defeats Antonio Silva via TKO (punches), 3:36 Round 1
Heavyweight bout: Roy Nelson defeats Dave Herman via KO (punch), 0:51 Round 1
Heavyweight bout: Stipe Miočić defeats Shane del Rosario via TKO (elbows), 3:14 Round 2
Heavyweight bout: Stefan Struve defeats Lavar Johnson via Submission (armbar), 1:05 Round 1
Preliminary Card on FX
Featherweight bout: Darren Elkins defeats Diego Brandao via unanimous decision (29-28, 29-28, 29-28)
Lightweight bout: Jamie Varner defeats Edson Barboza via TKO (Punches), 3:23 Round 1
Middleweight bout: C.B. Dollaway defeats Jason Miller via unanimous decision (29-28, 30-26, 29-28)
Welterweight bout: Dan Hardy defeats Duane Ludwig via KO (punch and elbows) 3:51, Round 1
Preliminary Card on Facebook
Lightweight bout: Paul Sass defeats Jacob Volkmann via Submission (triangle armbar), 1:54 Round 1
Light Heavyweight bout: Glover Teixeira defeats Kyle Kingsbury via Submission (arm-triangle choke), 1:53 Round 1
Featherweight bout: Mike Brown defeats Daniel Pineda via unanimous decision (29-28, 29-28, 29-28)