Gary Guiden of Muncie, Ind., gave Odell Leonard the worst beating of his professional career tonight to win the U.S. Boxing Association light middle-weight championship on a technical knockout in the fourth round.

Guiden, the No. 1 contender for the title stripped from Kansas City's Tony Chiaverini last year, hit Leonard almost from the opening bell with jabs and combinations before referee Mike DeFabis of Indianapolis stopped the beating 40 seconds into the fourth round of the scheduled 12-round fight.

Leonard, from Palmer Park, Md., the alleged first cousin of WBC welterweight champion Sugar Ray Leonard, stumbled to the dressing room three flights below the main room of the armory here, assisted by Dave Jacobs, his trainer, and Roland Kenner, his manager.

"That's the worst beating Odell has ever taken," said Jacobs.

Guiden (37-5 with 32 knockouts) had said he was confident going into the fight -- "Odell is a slugger, not a runner."

Nevertheless, Leonard (18-6 with 10 knockouts) should have done more running tonight.

"If we had to start over again," said Jacobs, who used to be in the Sugar Ray Leonard camp before a disagreement with Angelo Dundee, "we would have covered up and moved more in the early rounds."

Guiden stayed in close in the second round and began leading with his jab and coming back with his right. When Leonard covered up, Gideon squeezed inside and scored with uppercuts to the chin.

Guiden had Leonard on the ropes in the third and was punishing him with the same repertoire when Leonard's eye began to close.

"I'm glad the referee stopped it," said Jacobs. "It's always good to stop a fight before it gets too late. It just wasn't Odell's night. Every fighter has a night like this and Odell has his night tonight.

"We would like to get Guiden in Odell's hometown soon for a rematch, but we'll have to go back, regroup and see what happens."