By Tim Dahlberg
The Associated Press

LAS VEGAS - Cincinnatian Tim Austin made the mistake of trying to trade punches with a puncher, and it cost him his IBF bantamweight title.

Rafael Marquez caught Austin with a vicious right hand midway through the eighth round Saturday night, knocked him through the ropes with a combination and was pummeling him when the fight was finally stopped by referee Vic Drakulich.

It was the first defeat in an 11-year pro career for Austin, who fought on the 1992 Olympic team and was making the 10th defense of his 118-pound title.

Marquez, meanwhile, joined his brother Juan Manuel Marquez as a world champion with the win. Juan Manuel Marquez won the IBF featherweight title Feb. 1 when he stopped Manuel Medina.

"I'm very happy to join my brother as a world champion," Marquez said. "I didn't go for it early because he hit me with some shots to the body that really hurt."

Austin appeared as though he would lose by knockout when he was knocked through the bottom ring rope by a flurry of punches. But he somehow managed to climb back into the ring and get up at the count of nine.

The fight resumed and Austin fought back valiantly, but Marquez was all over him and Drakulich stepped between the two fighters at 2:20 of the eighth round.

Austin (25-1-1), of Cincinnati, had appeared hurt by a combination in the fourth round, but regained his momentum and appeared to be taking control of the fight as it went on. He was ahead by three points on two scorecards and one on a third after seven rounds.

Both fighters traded big head punches in the eighth round, but the Mexican challenger (29-3, 27 knockouts) then landed a right and another left-right that hurt Austin. He then followed him across the ring and landed the combination that put him through the ropes.

"My corner told me I had to quit wasting time so I just went for it all," Marquez said.

It was a bad night all together for Cincinnati fighters. Earlier, Olympic silver medalist Ricardo Williams was beaten in a 10-round fight by late substitute Juan Valenzuela.

Williams lost for the first time in his pro career, falling to 8-1 in an entertaining fight that Valenzuela won by six points on one scorecard and four on the other two.

"I expected a very strong opponent, after all, he was an Olympian," Valenzuela said. "He didn't have that much power, though, just a lot of speed.