Floyd Mayweather's exhibition fight with John Gotti III ended in a mass brawl when people stormed the ring following a controversial decision.
Referee Kenny Bayliss stopped the fight in the sixth round to the annoyance of Gotti, who then lashed out at 46-year-old Mayweather.
The ring was then swarmed with team members from both sides as Bayliss struggled to contain the drama.
Gotti III, 30, is the grandson of former New York crime boss John Gotti.
The melee kicked off a number of fights amongst the crowd in the FLA Live Arena in Florida and backstage.
In a video posted on social media, former boxing world champion Mayweather was filmed after the fight saying: "That's why they pay the big bucks, because I put on a show."
The arena had to be cleared by police, who threatened charges against fans who did not leave immediately.
Mayweather retired in 2017 with a record of 50-0 and has appeared in several exhibitions bouts against mixed martial arts and YouTube stars.
This was the first time his exhibition tour had returned to the United States since his eight-round bout with YouTuber Logan Paul in 2021.