Conor McGregor became the undisputed UFC featherweight champion with a sensational knockout of long time champ Jose Aldo after just 13 seconds in Las Vegas.

Just 13 seconds had gone by when McGregor connected with a  spectacular left hook punch that dropped Aldo to the canvas, completely knocked out.

Irish fans numbered at 10,000 in the MGM Grand Vegas venue cheered and chanted his name and went delirious as he was proclaimed victor.

Afterwards McGregor talked about huge pay days ahead, matching the best in professional boxing and also the possibility of fighting at home in Ireland.

McGregor was waved off by the referee as he attempted to follow up and had his hand raised in victory. Aldo 25-2 who held the title for 10 years was helpless.

It was McGregor's fifth consecutive knockout, one he had predicted.

"What I say happens, happens," McGregor said. "There is no doubt now."

Aldo had previously won 18 consecutive fights over the last 10 years, but McGregor's victory was the fastest title knockout  in UFC history, surpassing Ronda Rousey's 14-second win over Cat Zingano at UFC 184 in February.

"Precision beats power, and timing beats speed," McGregor said. "Jose was a phenomenal champion. He deserved to go a little bit longer, but I still feel at the end of the day, precision beats power and timing beats speed. That's what happened."

“I’ve worked my whole life for those 13 seconds” McGregor told the Irish Independent.

"Tonight was a phenomenal night. A $10.1million gate, a phenomenal number. We've done it again," said McGregor. 

"What did Mayweather-Pacquiao do? $72 million. That's [the aim]," said the Dubliner as Irish fans swarmed through the casinos of Sin City. "I'm catching up [with Mayweather] I'm only 27, those motherf***ers were 40. I'm only warming up.

"I said to [UFC owners] Lorenzo Fertitta and Dana White, I'm breaking these big numbers, I'm breaking these half a billion dollar revenue numbers like the Mayweather-Pacquiao fight. At 27 years of age I stand here as the unified world champion with back-to-back gate records at the MGM Grand. This is trending as the highest PPV I believe of all time for the UFC.

"At 27 years of age with every record in the book, with divisions above ready for me to go at, super fights left and right. I'm going straight up, I'm bringing these big numbers, the sky is the limit. Anything can happen."

"If they offer me Croke Park, or if they offer me the football [Aviva] stadium, you're damn right I'm gonna take it," he said before agreeing that perhaps he could just lay down the law himself.

"Maybe I can [demand it] these days. But I'm gonna sit back in the shadows for christmas and plot. Then I'll come back."

"I said his right hand would get him into trouble, he would overload on his right hand," he said of the step-in that ended Aldo's historic reign at the top. "I said I'd stop and land the left hook and that's what happened. If you can see it, and have the courage enough to speak it, it will happen, I see these shots, I see the sequences and I don't shy away from them.

"A lot of the time people believe in certain things but they keep it to themselves, they don't put it out there.”

"Jose has been a phenomenal champion," he said, before heading off to his after-party. "It would have been nice if the contest had stretched out a little longer. I still feel the same process would have happened. I respect jose, I wish him well but we're on to the next chapter.

"It's not the same when you fight me, it's a whole other ball game, a whole other pressure bubble.

"When they show up and face me, they are re-energised. They become better. Maybe Jose should go back and regroup."