The odds were close, according to BetDSI.com, but it was an upset nonetheless.

It took only 13 seconds for Conor McGregor (-109) to finish Jose Aldo (-111) with a left hook and two follow-up hammerfists in the UFC 194 main event on Saturday at the MGM Grand Garden Arena in Las Vegas. The performance made the “Notorious” Irishman the second undisputed featherweight champion in Ultimate Fighting Championship history and gave Aldo his first defeat in more than a decade.

McGregor has won his last 15 fights, finishing 14 of them.

In the co-main event, Luke Rockhold (+137) dethroned Chris Weidman (-168) to become middleweight champion. The American Kickboxing Academy ace caught an ill-timed kick in the third round, landed a takedown, advanced to mount and rained heavy elbows and punches. The fight was allowed to continue, with Rockhold battering the Serra-Longo Fight Team rep until referee Herb Dean had seen enough.

In another mild upset on the main card, American Top Team brute Yoel Romero (+116) eked out a split decision over Ronaldo Souza (-138). The first round was Romero’s strongest, as the onetime Olympic silver medalist nearly finished it with a spinning backfist and follow-up punches and elbows. Romero is 7-0 in the UFC and has emerged as the No. 1 contender at 185 pounds.

Meanwhile, Demian Maia (+104) used his tried-and-tested Brazilian jiu-jitsu skills to put on a grappling and ground-and-pound clinic against Gunnar Nelson (-124), cruising to a unanimous decision over the Renzo Gracie protégé. Scores were 30-26, 30-25 and 30-25 for Maia, who is on a four-fight winning streak at 170 pounds.

The prelims saw a few upsets, too.

“The Ultimate Fighter: Brazil” Season 3 winner Warlley Alves (+114) stayed undefeated with a guard-jump guillotine choke submission on American Top Team prospect Colby Covington (-134). The choke ended it 1:26 into round one, moving Alves to 10-0.

Elsewhere, the athleticism and well-rounded skills of promising Xtreme Couture export Kevin Lee (-585) were no match for the brilliant timing and powerful counter right hand of multiple-time Brazilian jiu-jitsu world champion Leonardo Santos (+425). He put an end to Lee’s four-fight winning streak and left with a $50,000 “Performance of the Night” bonus after scoring the biggest upset on the card.

Finally, Yancy Medeiros (+145) took a razor-thin unanimous decision from Tristar Gym’s John Makdessi (-170) at 155 pounds. The Hawaiian knocked down Makdessi with a left hook in the third round, his efforts rewarded by judges Lester Griffin, 29-28, and Marcos Rosales, 29-28.