Floyd Mayweather and Conor McGregor went face-to-face for the first time on Tuesday night in a press conference in Los Angeles.

McGregor was made to wait for 'Money' to emerge and when he did, the Irishman hurled abused at his American opponent as they faced each other for a stare off.

Mayweather, on the other hand, stayed completely quiet.

It didn't take long for the expletives to begin, with 'the Notorious' starting his speech by predicting he would knock out Mayweather inside four rounds.

"Baby we made it!" he began. "This boxing conference is different to what I'm used to. I'm honoured to be here. Somebodies 0 has got to go.

"He's in a tracksuit, he can't even afford a suit anymore! He is f*****.  I'm going to knock him out inside four rounds, mark my words.

"I'm just enjoying myself. That's it. He will be unconscious in four rounds. He's never experienced someone like me. I don't fear him.

"This is a limited set of rules that makes this half a fight, a quarter of a fight. If this was a true fight, it wouldn't even take one round."

Mayweather's boxing record currently stands at 49-0 and McGregor believes he can inflict his first career defeat when they meet on August 26 at the T-Mobile Arena, Las Vegas.

But as you would expect, Mayweather was having absolutely none of it and hit back at McGregor when it was his turn to speak.

The 40-year-old began by chanting with his fans and then said: "I don't give a f*** if we do this in the Octagon. I'm going to knock this b**** out."

Mayweather's vow to win by knockout provoked a mixture of cheers and boos from the crowd, but then McGregor delivered an epic response to bring the house down.

In the video below from 56:55, McGregor hilariously replied: "Yeah right. You haven't knocked anyone out for 20 years!"

MCGREGOR DESTROYS MAYWEATHER

Brilliant. Mayweather is renowned for being a defensive boxer and only on four occasions has he won by KO after flooring his opponent, the last being Victor Ortiz in 2011.

The manner of Mayweather's last genuine knockout was controversial, too, because the American twice sucker punched Ortiz after they touched gloves.