US former professional boxer Evander Holyfield falls during a fight against Brazilian martial artist Vitor Belfort in Hollywood, Florida on Saturday. Photo: VCG

Former heavyweight world champion Evander Holyfield looked all of his 58 years in a first-round technical knockout loss to mixed martial arts star Vitor Belfort on Saturday.

With former US president Donald Trump providing ringside commentary for the spectacle at Seminole Hard Rock casino in Hollywood, Florida, Brazil's Belfort unleashed an early flurry that ended with Holyfield slipping through the ropes.

The American ring great regained his feet only to be sent to the canvas by a combination from Belfort. He beat the count, but after he absorbed another flurry of blows without throwing any the referee stopped the fight despite Holyfield's objections.

"I wasn't hurt," insisted Holyfield, who called the decision to stop the fight "kind of sad."

"It is what it is," he said. "I think it's a bad call."

Holyfield was fighting for the first time since he defeated Brian Nielsen in 2011 to cap a glorious ring career.

Holyfield won 1984 Olympic gold as a light heavyweight and went on to dominate the professional cruiserweight division before entering prize fighting lore as a heavyweight.

He's best known for a championship heavyweight run that included two wins over Mike Tyson, one of them the infamous "Bite Fight," a win over George Foreman, and one win over Riddick Bowe in their punishing trilogy.

Holyfield (44-10 with two drawn and 29 knockouts) accepted the Belfort fight on eight days' notice after Oscar de la Hoya tested positive for COVID-19.

Holyfield said he was ready, having been preparing for a proposed comeback bout against Kevin McBride that didn't come off.

Asked after the fight if he was still interested in making a rematch with his old nemesis Tyson, Holyfield said, "Of course."

But even Trump, who tirelessly boosted Holyfield throughout his undercard commentary, seemed taken aback by the ex-champ's performance.

"No, he's not the same," Trump said. "Right from the beginning he was not the same fighter. He lost a lot. It was not Evander Holyfield."

Trump received a rapturous welcome from fans at the Florida venue, where he arrived after visiting New York on the 20th anniversary of the 9/11 attacks.

He got in a dig at President Joe Biden and a plug for his friend Dana White, promoter of mixed martial arts brand Ultimate Fighting Championship, in low key commentary alongside his son Donald Trump Jr.

The former president is no stranger to boxing, his hosting of major fights at his hotels and casinos having earned him a place in New Jersey's boxing Hall of Fame.

Trump's commentary for the card put together by Triller, the music video app that is trying to break into boxing with its Triller Fight Club streaming platform, included remembrances of fights and fighters past along with random observations on the sport.

"It's like elections, it could be rigged, too," Trump noted of some questionable fight results he's seen in the past.