SAN ANTONIO—Welterweight Oscar Diaz spent the night in surgery for bleeding on the brain and is in a coma after collapsing between rounds of a nationally televised bout in his hometown.

The 25-year-old fighter was taking a beating from Delvin Rodriguez on Wednesday night at San Antonio’s Municipal Auditorium when he collapsed on his stool entering the 11th round.

Ron Katz, a matchmaker for Star Boxing, which promoted the fight, told The Associated Press by phone that Diaz was in a coma and not breathing on his own after the surgery.

“My understanding is they had to remove, on the left side, a part of his cranium to get the swelling down,” Katz said, citing information he said came from Diaz promoter Donna Duva Brooks. Katz said Brooks was at University Hospital in San Antonio with Diaz.

Katz said Diaz’s vital signs, like his blood pressure and temperature, were good.

“It’s touch-and-go, very critical,” Katz said. “But the doctor, from what I’ve gathered from Donna, was optimistic.”

Katz said injuries like Diaz’s are usually career-ending. Diaz came into the fight for the USBA welterweight championship with a 26-2 record and 12 knockouts.

“What one hopes for is that he pulls through,” Katz said, calling Diaz a “strong kid.”

Katz, who was at the fight, said Diaz had been taking heavy blows before he collapsed, but that “he was in there pitching.”

There was no indication anything was wrong, Katz said, until Diaz stood up to begin the 11th round, then put his hands to his head and “yelped” before collapsing.

Referees stopped the fight, declaring Rodriguez the winner by technical knockout, and doctors jumped into the ring to attend to Diaz, place him on a stretcher and take him to University Hospital.

“EMS (emergency medical services) reacted so quickly and got him to the trauma center so fast that that really gave him a fighting chance,” Katz said.

Hospital spokeswoman Leni Kirkman said she had no new information on the 5-foot-10, 147-pound fighter Thursday morning. She did not immediately return a phone call later in the day.