Conor McGregor has denied carrying a secret injury into his comeback fight following an embarrassing 60-second performance that will have fans feeling ripped off.

The 37-year-old Irish combat sports legend failed to land a blow on old rival Max Holloway as the pair headlined UFC 329 in Nevada on Sunday.

Conor McGregor jumps into the air for a kick as he fights Max Holloway. John Locher

The fight began with McGregor racing towards Holloway and leaping off the ground in an attempted flying roundhouse kick, which missed by several inches, before he fell to the canvas.

He tried another high kick, again falling to the canvas, before dropping a third time and being pummelled by Holloway before the referee stepped in to end the farce.

Replays showed McGregor’s right knee buckle badly as he landed the first time, and UFC boss Dana White later revealed the Irishman has likely ruptured the anterior cruciate ligament in his right knee.

“I was expecting at least a one-round war,” White told media.

“Who knew what Conor was capable of as far as cardio and whatever else after a five-year layoff.

“And there we go, we’re assuming a blown ACL. Doctors think the same thing, too.”

But there is speculation McGregor was already injured before the fight began, putting a massive question mark over the legitimacy of the bout.

It was his first UFC fight in five years, and his last ended with a badly broken leg. In the years since then McGregor has been dogged by allegations of rape and drug abuse.

Nonetheless, fight fans forked out their hard earned cash to watch him take on Holloway a second time, only for the bout to end before it really began.

Vision was played of a moment before the fight, when McGregor was taking his shoes off. He appeared to wince in pain and hold his right leg in the air, leading commentators to speculate whether there was a pre-existing injury that wasn’t made public.

The Irishman later took to social media to deny the claims.

Conor McGregor wobbles on one leg pre-fight. Main Event

“My head gasket is gone. Destroyed. I had no injury / injuries going into the fight,” McGregor posted on X.

“I was throwing kicks, planted and jumping, all throughout camp as well as backstage before the fight. This came out of nowhere.

“I am beyond dark here. I can only describe it as hell.”

UFC commentator and podcaster Joe Rogan pointed out it was the same leg McGregor snapped five years ago, and criticised the flying roundhouse kick attempt.

“He just tried a crazy move. He tried to jump and roundhouse kick,” Rogan said.

“If you don’t land in a good way with the supporting leg, you put so much pressure on that knee.

“He landed with his knee in the worst position. He blew his ACL out, 100 per cent.

Conor McGregor of Ireland reacts after sustaining a leg injury and losing in the first round of his fight with Max Holloway. Ian Maule

“It sucks. You just don’t do that.

“It might have been the game plan. He threw the kick with the broken leg… maybe to prove he could still kick with that leg? I don’t know, no one will know, only Conor knows.”

Former UFC fighter Daniel Cormier could not believe what happened.

“It’s like somebody took my candy from me, I’m so sad,” Cormier said.

“It’s so crazy how sad I am.”

Fellow commentator Joe Anik said the arena was in “stunned disbelief”.

“It really seemed like he was back for the right reasons, for legacy, and now potentially there will be another rebuild… or not, we shall see,” Anik said.

Holloway wants a third fight with McGregor.

The crowd booed the Irishman as he hobbled out of the arena, but Holloway told them to get ready for a trilogy bout.

“Let’s give it up for Conor, what an absolute animal,” Holloway said as his rival left the scene.

“When we were in here, I kept trying to call the fight (off), and he kept asking to fight on. But you guys are lucky, because there’s going to be a Holloway v McGregor three now.”