Conor McGregor SNAPS leg in horror injury as he suffers defeat to Poirier at UFC 264 (VIDEO)

Conor McGregor suffered a gruesome leg injury as his trilogy fight with Dustin Poirier was stopped after the first round at UFC 264 in Las Vegas.

McGregor’s lower left leg snapped as he took a step backwards after throwing a punch, with the fight being called off by doctors at the end of the round as the Irishman was down in agony.

The contest was awarded to Poirier as a TKO doctor stoppage as the American claimed outright bragging rights over his Irish rival with two wins from three in their trilogy.  

WARNING: GRAPHIC

Poirier had enjoyed the better of the opening round, dominating McGregor on the ground and catching him with several clean shots.

The Irishman had started with a barrage of low kicks before the action went to the mat, as Poirier later claimed that the damage he had done when checking McGregor's kicks had led to his ankle snapping later in the round.

“He fractured it in one of the checks at the beginning of the fight… It was probably cracked and on the twist of the punch [it broke],” Poirier said.

Poirier earned a second win in a row over McGregor. © USA Today Sports

The pair’s third fight had been preceded by some toxic trash talk from McGregor in which he had threatened to “murder” his rival and also suggested Poirier's wife had tried to make contact with him.

“Murder stuff, there’s no coming back from that,” Poirier said after the fight.

“This guy’s a dirtbag man. Anybody booing, you can kiss my whole a**hole,” Poirier added to the disappointed full house at the T-Mobile Arena.

“Karma’s not a b*tch, she’s a mirror.”

A stricken McGregor gave his post-fight interview from the canvas, still fuming at his rival and goading him about his wife.

“This is not over. If I have to take this outside with him, I don’t care,” McGregor raged.

“There was no check… Your wife is in my DMs, baby.”

McGregor left the octagon on a stretcher, still saluting his fans but having suffered a third defeat in his last four fights.

Given the nature of the ending of the contest, there will no doubt be a clamor for McGregor and Poirier to run it back yet again.

The American, however, may prefer to set his sights on a shot at the lightweight title owned by Brazil’s Charles Oliveira – an opportunity which ‘The Diamond’ passed up following his last victory over McGregor in Abu Dhabi in January.

McGregor, 32, remains his sport’s biggest draw but will now need to recover from his horrific injury and perhaps reconsider his fighting options after another galling night in the octagon.