Lightweight Louis Villalta collapsed in his dressing room Saturday night, minutes after losing a 12-round fight against Ricky Quiles in Florida.
The 35-year-old was immediately taken to nearby North Broward Regional Medical Center, where he remains unconscious.
Villalta had just lost his regional title but seemed fine until he got back into his dressing room. Apparently, he complained of headaches shortly before his blackout.
Villalta collapsed just before the night's heavyweight main event featuring former WBO champion Ray Mercer v Steve Pannell. After a 30 minute delay the fight went ahead and Mercer won in three.