NORTH KANSAS CITY, Mo. -- Boxer Randie Carver underwent brain surgery and remained in critical condition Monday after being knocked out during a fight at Harrah's North Kansas City Casino.

The surgery was completed late Sunday. Carver, 25, of Kansas City, Mo., was knocked out in the 10th round of a scheduled 12-round bout with Kabary Salem.

Carver's family requested that no other information be released on his condition, Kim Shopper, a spokeswoman for North Kansas City Hospital, said Monday.

Randy Singer, director of Missouri's Division of Professional Registration, which oversees the boxing-regulating Missouri Athletic Commission, said the commission's staffers were going to review a videotape of the fight Monday. But he said the commission's authority was limited to considering whether fight officials, who it licenses, acted properly.

Carver, who billed himself "the Natural," is a former Golden Gloves champion who won the North American Boxing Federation super middleweight championship at the casino last year. He brought a 23-0-1 record into the championship fight, televised on the Fox Sports Net.

Carver, repeatedly head-butted in the early rounds, fell sluggishly to the canvas in the 10th round after taking an overhand right and a straight left from Salem.

He tried on four occasions to rise, but couldn't get to his knees.

"He starts wobbling, he falls, he tries to get back up and he can't," said Pete Young, who watched the bout at ringside. "He rolls ... and he's not strong enough to even get back to his feet. He falls back down to the canvas, and then the eight-count was over and he stayed down."

After referee Ross Strada ruled a knockout, physician Michael Poppa rushed into the ring. Carver's eyes appeared to go back in his head, and he lost consciousness.

Paramedics gave Carver oxygen, put a breathing tube in his mouth and inserted an IV. They worked on him for close to 20 minutes before rushing him to the hospital. Carver never appeared to regain consciousness.

Many members of Carver's family rushed to ringside in tears, and officials had to restrain some who tried to get into the ring.

Trainer George Smith, who considered Carver a son, was upset at the number of times Salem head-butted Carver. In the second round, Carver had a nasty cut in the corner of his right eye and one under his left eye. Strada warned Salem twice, but ruled the head-butts accidental.

"He got head-butted more than he should have," Smith said. "But he seemed fine and responsive. He reacted to my statements."

In the eighth round, Carver looked noticeably tired, and had a hard time getting off the ropes when Salem pushed him.

"He looked tired, he was dry, and he wasn't sweating a lot," said Poppa, the physician. "It was a wrestling match, but when I checked his eyes, he looked good, and the cuts were superficial."

Salem, who has a 12-1 record, expressed concern for Carver's well-being. He said, though, that he had no regrets about the way he fought Carver, figuring a knockout was his only chance.

"It's his hometown, you know?" the 31-year-old said. "If it goes 12 rounds, he wins.

"I hope he's fine," he added. "I feel bad. What can I say? It's a fight."

On Jan. 29, boxer Fernando Ibarra suffered a brain injury after he was knocked out by Ratanachai Vorapin, a top-ranked contender for the International Boxing Federation title, in the sixth round of a fight at the Regal Riverfront Hotel in St. Louis. Ibarra underwent surgery and is recovering.