LAS VEGAS — (The Notorious) Conor McGregor backed up his trash talk with his fists Saturday night at UFC 194, knocking out Jose Aldo in just 13 seconds to become undisputed featherweight champion.
It was short and violent.
Aldo missed with a right and McGregor floored the champion with a left, adding a pair of hammer-fists before referee John McCarthy stepped in.
"He was a phenomenal champion ... But precision beats power," said McGregor.
Aldo (25-2) had won his last 18 fights and has not lost since November 2005. McGregor was on a 14-bout win streak that dates back to November 2010.
Aldo entered the cage as champion while the brash Irishman arrived as interim title-holder for a win over Chad (Money) Mendes while Aldo was out injured.
McGregor (19-2) left with the belt.
"I think we need a rematch. It wasn't really a fight," Aldo said through an interpreter.
The crowd roared as McGregor — clad in green compression shorts — entered first, with "Ole Ole" chants from the stands competing with his Notorious B.I.G. entrance music. Aldo followed him to "Run This Town" by Jay-Z with Rihanna and Kanye West.
The two did not touch gloves before the opening round. The end came soon after.
In the co-main event at the MGM Grand Garden Arena, No. 1 contender Luke Rockhold dethroned middleweight champion Chris Weidman.
Rockhold (15-2-0) beat Weidman up on the ground in the third round and did the same in the fourth, before referee Herb Dean finally stepped in at 3:12.
"It was Luke's night," said Weidman, his face a roadmap of cuts and welts.
A middleweight title fight that had been relatively even turned in the third when Weidman tried a spinning kick. Rockhold evaded the kick, grabbed Weidman and took him down for the first time in his UFC career. Rockhold then mounted Weidman and carved his face open with repeated strikes. The beatdown seemed to go on forever, with Dean allowing the round to end.
Weidman's face was a mess as he came out for the fourth. Weidman soon found himself on the bottom again and the beating continued.
Weidman (13-1-0) had previously beaten a Who's Who of opponents, including former champions Anderson Silva (twice), Lyota (The Dragon) Machida and Vitor (The Phenom) Belfort.
Rockhold, a former Strikeforce champion, limped out of the cage with the title.
The 29-year-old Aldo, who at five foot seven is two inches shorter than the Irishman, is ranked the UFC's top pound-for-pound fighter. McGregor, 27, is No. 12 in the pound-for-pound rankings, just below Ronda Rousey.
Aldo and McGregor were originally slated to meet at UFC 189 in July. And the fighters talked smack in Toronto, Rio de Janeiro, Las Vegas, Los Angeles, Boston, New York City and Dublin, criss-crossing North America in separate private jets before heading to Europe to hype that fight.
They almost came to blows in Toronto when McGregor slapped Aldo on the back while waiting to go on air during a morning visit to CTV's "Canada AM.''
UFC president Dana White dubbed it the "war tour.''
But Aldo withdrew less than two weeks before the fight due to a rib injury. McGregor fought Mendes instead, stopping him late in the second round for the interim title.
The sandpaper-like McGregor, a former plumber who has yet to meet a microphone or camera he doesn't like, has taken one verbal shot after another at Aldo, whose lack of English restricted his comebacks. But the Brazilian looked calm and businesslike in the buildup to this fight.
Aldo is the only undisputed featherweight champion the UFC has ever had. He won the 145-pound crown in the WEC in November 2009 and became UFC champ a year later when the UFC bought and absorbed the WEC.
The win earned McGregor a spot on the cover of the UFC's next video game, alongside former bantamweight champion (Rowdy) Ronda Rousey.
Yoel (Soldier of God) Romero, ranked third among middleweight contenders, hung on to win a split (29-27, 28-29, 29-28) decision over No. 2 Ronaldo (Jacare) Souza of Brazil.
Romero won his seventh straight while snapping Souza's eight-fight win streak.
"I am ready for everybody," said Romero.
Romero took it to Souza on the ground in the first round after dropping him with a spinning back fist. The wobbly Brazilian was unsure where to go when the round ended. Souza recovered and hurt Romero, who ran out of gas as the fight progressed, at the fence in the third before taking him down.
Romero, 38, won a silver medal in freestyle wrestling for Cuba at the 2000 Olympics. Souza, 36, is a former Strikeforce title-holder and world Brazilian jiu-jitsu champion.
Demian Maia, another former jiu-jitsu world champion ranked sixth among welterweight contenders, outgrappled No. 12 Gunnar (Gunni) Nelson — a black belt himself — while administering plenty of ground-and-pound pain along the way to a lopsided 30-26, 30-25, 30-25 decision.
Max (Blessed) Holloway, ranked fifth among featherweight contenders, beat No. 8 Jeremy (Lil' Heathen) Stephens by a unanimous (30-27, 30-27, 29-28) decision for his eighth straight win.
Montreal lightweight John (The Bull) Makdessi, returning after a broken jaw in a loss to Donald (Cowboy) Cerrone, lost a split decision to Yancy Medeiros on the undercard.
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Neil Davidson, The Canadian Press