LAS VEGAS -- Roberto Duran all but pleaded "no mas" for the second time in his career.
Duran, a four-time former champion who turns 40 in June, stopped fighting in the sixth round of his scheduled 10-round super-middleweight bout last night with journeyman Pat Lawlor of San Francisco.
Lawler threw a right hand that glanced off Duran's elbow and banged into his right rib cage. The Panamanian doubled up in pain and walked slowly to his corner.
Referee Vic Drakulich called timeout and signaled for ring physician Flip Homansky to examine Duran.
Homansky said the blow had injured a nerve in Duran's right shoulder and stopped the match.
"I threw a jab and a tendon cracked," Duran said. "The doctor said I tore my biceps in my left shoulder. Even though I had one arm, I could still fight."
Drakulich said: "If he can't raise his arm, he can't fight. I had no choice."
Duran, who said he first hurt the shoulder while training two weeks ago in Miami, suffered his greatest boxing embarrassment in November 1980, when he surrendered to Sugar Ray Leonard in their second welterweight title fight in New Orleans.
Frustrated by Leonard's elusiveness and clowning tactics, Duran quit in the eighth round, complaining of stomach cramps.
He resurrected his career, beating Davey Moore in 1983 to claim the World Boxing Association junior middleweight crown and six years later upsetting Iran Barkley to win the World Boxing Council middleweight title.
But last night Duran looked like an old boxer fighting simply for a payday. Lawlor, an unranked club fighter, showed little respect for Duran. He was leading on all three score cards before the bizarre ending.
Duran weighed 168 pounds, the class limit for the 10-round super-middleweight fight. Lawlor, 27, is 15-1.