ATLANTIC CITY, N.J.-- Two people were arrested and a boxing official was injured early Sunday when a chair-throwing melee broke out after a heavyweight bout.

More than 50 people were involved in the fight, which came after Hasim Rahman was knocked out -- and out of the ring -- by Oleg Maskaev of Russia.

"It was a complete melee," police Sgt. Guy Curcione said.

Steve Smoger, an alternate referee for the fight who was sitting ringside, was struck in the back of the head by a thrown chair. He was treated at the scene but did not require stitches.

There were no other injuries, police said.

Maskaev hit Rahman in the head with an overhand right 40 seconds into the eighth round, knocking him backward through the ropes and ending the scheduled 10-round fight.

Rahman fell out of the ring, landing on a scorer's table and falling off, hitting his head on the floor. Then someone threw a chair into the ringside seats, triggering a 10-minute free-for-all involving dozens of spectators and security guards in the Convention Hall ballroom.

Curcione was at the scene and said 50 to 70 people fought security guards and each other. He said additional police had to be called in off the street.

It wasn't clear what started the brawl outside the ring. Witnesses said a member of Rahman's family jumped over seats to get to him after the knockout.

Julius Freedman, 40, of Baltimore and Steven Higgs, 22, of Wyandanch, N.Y., were charged with disorderly conduct. They were released on summonses, said police Sgt. Michael Tullio.

The postfight mayhem occurred before about 1,500 fans.

Maskaev was trailing on two of the three judges' cards when he won the fight, boosting his record to 18-2. Rahman of Baltimore was not seriously hurt.

In the co-feature, unbeaten Derrick Jefferson of Detroit knocked out Maurice Harris of Newark in the sixth round of their 10-round bout.

Jefferson won with a thunderous left hook at 2:52 of the round. Harris, a late substitute for Lance Whitaker, appeared unconscious before he even hit the canvas.

"I thought I was ready to take him out, but he got me real good," Harris said. "It was just when I thought I had him."

Jefferson, a 6-foot-6, 246-pound former basketball player, is 31 and didn't start boxing until he was 27. He boosted his record to 22-0.

"I knew if I knocked him down one more time, he wouldn't get up," he said. "And he didn't."