McGregor’s left ankle appeared to snap 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.
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.