Wow!!!! Conor McGregor Knockouts Jose Aldo at #UFC194!!!!! https://t.co/zEbZursoW6

— UFC Europe (@UFCEurope) December 13, 2015

The enigmatic Dubliner caught Aldo with a stinging left hand to the chin which sent him to the canvas, and he followed up with a couple of hammerfists before referee John McCarthy stopped the contest.

McGregor, who was the interim belt holder following the Brazilian's injury-enforced withdrawal prior to their scheduled July clash, is now the new and undisputed UFC featherweight champion of the world.

It was Aldo's first defeat in the octagon in over a decade and speaking afterwards in front of the thousands of Irish fans inside the MGM Grand Garden Arena, McGregor knew that his greater punching ability would prove decisive.

"Nobody can take that left hand shot," he insisted. "He's powerful and he's fast. But precision beats power, and timing beats speed, and that's what you saw there. I feel for Jose. He was a phenomenal champion. We deserved to go a little bit longer. But it would've happened sooner or later.

"No power. No power. Just precision. No speed. Just timing. These are fundamentals. That's all it takes. Yesterday at the weigh-in, I didn't want to get off the stage. I wanted to embrace every bit of it. Sometimes, it's over before you even know it."

McGregor came out quickly from the off, first with a kick and then as the quick-moving Aldo launched forward, the 27-year-old Irishman threw a straight left that toppled his opponent. The accuracy of the punch was all the more impressive given that Aldo also connected with a right hand to McGregor's face.

The fight was over in UFC title fight record time, beating the 14-second mark set by Ronda Rousey, and took McGregor's record to 19-2 MMA, 7-0 UFC as he continues to climb the pound-for-pound rankings.

Aldo (25-2 MMA, 7-1 UFC) suffered his first MMA loss since November 2005 and handed over the UFC belt he has held for the last five years through 18 fights, 10 title fights and nine title defences.

With blood visible from a cut on his face, Aldo said through a translator: "I think I need a rematch since it really was not a fight. I think we need to get back in here. (His trash talk) didn't affect me at all. We'll have to come back in here and it's on to the next at this point."

McGregor's first title defence, whether that is a rematch against Aldo or against Frankie Edgar who knocked out Chad Mendes at Friday's Ultimate Fighter 22 finale, is on course to take place at Croke Park next year.

UFC President Dana White said in recent months: "If he beats Jose Aldo in Las Vegas (in December), the next fight will be at Croke Park. We told him he could defend his title at Croke Park."