McGregor vows to end Mayweather’s unbeaten record and Knock him out inside four rounds

Conor McGregor says he will knock out Floyd Mayweather inside four rounds in their Las Vegas showdown.

The UFC champion will make his professional boxing debut against the 49-0 undefeated former world champion at the T-Mobile Arena on August 26.

The pair have traded barbs before and since the fight was announced, but both were in particularly spiky form as the world tour to promote their bout got under way.

McGregor took to the rostrum first, taking shots at Mayweather’s reported recent request to be allowed an extension on his 2015 tax bill in a typically expletive-laden performance.

But ‘The Notorious’ drew the biggest cheer from a fired-up crowd in the Staples Center when issuing his big-fight prediction.

In a crisp three-piece suit, McGregor began with a sartorial blow: “He’s in a f*****g tracksuit! He can’t even afford a suit anymore.

Here. We. Go. @TheNotoriousMMA #MayweatherMcGregor