Conor McGregor’s return against Max Holloway at UFC 329 in Las Vegas ended after just 69 seconds of the first round because of a knee injury.

Fighting for the first time in more than five years, the 37-year-old McGregor flew across the ring with a left roundhouse kick when the bout started and landed awkwardly on his right knee.

After attempting to kick and strike Holloway (28-9-0) two more times, it was clear McGregor (22-7-0) could not finish the scheduled five-round welterweight bout.

“I mean, I was expecting at least a one-round war,” the UFC chief executive, Dana White, said after the fight. “Who knew what Conor was capable of as far as cardio, whatever else, after a five-year layoff, and there you go. We’re assuming a blown ACL [anterior cruciate ligament]. I’m no doctor, but that’s what I figured when I saw it, and doctors think the same thing too.”

McGregor had gone into the fight as the underdog with the bookies.

Holloway said: “What can I say? I had him weak in the knees I guess. So much hype. We’ve got to run it back one more time. For it to end like this sucks.”

Conor McGregor and Max Holloway fought Saturday night in Las Vegas in a rematch of their 2013 featherweight bout. Photograph: Cooper Neill/Zuffa LLC

McGregor, who strolled to the ring to the sounds of the Notorious BIG’s Hypnotize and the roar of the sold-out crowd at T-Mobile Arena, last fought five years and a day before the bout on Saturday night.

In what McGregor called “the comeback of all comebacks in sports history”, the bout was a rematch of a 2013 featherweight fight which the Irishman won by unanimous decision.

After the fight on Saturday, McGregor denied he had been injured in the runup to the event.

“I was throwing kicks, planted and jumping, all throughout camp as well as backstage before the fight,” McGregor wrote on social media. “This came out of nowhere. I am beyond dark here. I can only describe it as hell.”

McGregor had not fought since breaking his left leg in a 2021 defeat against the American Dustin ­Poirier. McGregor had been the UFC’s most marketable star before that injury, in 2016 becoming the first to hold two titles simultaneously at dif­ferent weights. He ­reportedly earned more than $100m after losing a ­boxing ­superfight against Floyd ­Mayweather Jr in 2017.

McGregor was also embroiled in multiple lawsuits during his time away from the octagon, and became aligned with hard-right figures ­during an aborted run for the Irish ­presidency.

McGregor’s last UFC victory was a 40-second triumph against the American Donald Cerrone in January 2020.