Puerto Rico's Miguel Cotto avenged his controversial loss to Antonio Margarito three years ago when he beat the Mexican Saturday to retain his World Boxing Association (WBA) super-middleweight world title. Referee Steve Smogner stopped the fight before the start of the 10th round when ringside doctors ruled that Margarito was not fit enough to continue. Margarito's right eye, which had required surgery after he was brutally beaten by Manny Pacquiao last year, had closed shut and left him half blind after he had been repeatedly battered by Cotto. The Mexican's corner begged the officials to let the fight continue but the physicians called a halt to proceedings despite howls of protests from the packed crowd at Madison Square Garden. “His eye was gradually closing. I felt it was safer to stop the fight,” doctor Barry Jordan said. “His lid was completely closed for three rounds. He had no vision in that eye. I think it would have been dangerous for him to go back in.” Cotto, who improved his career record to 37-2 (30 KO), was well ahead on points when the fight was stopped, with all three judges having him 89-82 in front. The two fighters are sworn enemies and even when the bout ended they continued taunting each other with Cotto triumphantly marching over to his vanquished opponent's corner. “He means nothing to me,” Cotto said. “(I) just (wanted) to look at him and taste my victory on him.” Margarito, one of the most controversial figures in the sport after he was banned for a year for using illegal hand wraps, insisted he could have gone on and the officials were wrong to stop the fight. Margarito fell to 38-8, (27 KO). In an undercard bout, Brandon Rios stopped John Murray in the 11th round after battering the Englishman against the ropes and forcing the referee to step in. Rios, who now has a 29-0-1 record, had surrendered his WBA lightweight title when he failed to make the 135-pound (61-kilogram) weight Friday night. He could win the fight, just not the title. Delvin Rodriguez beat Pawel Wolak by unanimous decision in a junior middleweight bout, landing 65 of his 101 power shots in the final round. Also, Mike Jones won a unanimous decision over Sebastian Lujan and will get a fight for the vacant IBF welterweight title next year against Randall Bailey. Moreno, Mares retain titles In California, Anselmo Moreno retained his WBA bantamweight title with a unanimous decision over Australian challenger Vic Darchinyan at the Honda Center Arena Saturday. In the main event doubleheader, Abner Mares kept his unbeaten record intact by beating Joseph Agbeko also by unanimous decision to retain his IBF bantamweight belt.