LAS VEGAS // Miguel Cotto, the Puerto Rican super-welterweight, stopped his Nicaraguan challenger Ricardo Mayorga in the 12th and final round to retain his WBA belt.
The end of the contest came when Cotto (36-2, 29 KOs), who was well ahead on the judges' scorecards, caught Mayorga with a short left hook that sent the challenger staggering backward and down on one knee.
Mayorga beat the count but a follow-up barrage backed him into a corner, where he draped his arms on the ropes and signalled to Robert Byrd, the referee, that he had had enough and the official stopped the contest.
"It was a really good fight with an amazing finish," Cotto said. "He is a very strong fighter.
"He hit me with some really good shots."
Mayorga claimed that during the exchange of punches that resulted in his knock-down, he took a painful blow to his left thumb.
"I felt my thumb touch the back of my hand," he said.
"I tried to finish the final round but the pain was too much. I don't care about my thumb. I didn't want it to end like that. I tried to close my fist, but I couldn't."
Mayorga, (29-8-1, 23 KOs), a former welterweight champion, knew that his best chance of victory was to goad the more skilful Cotto into a brawl. On several occasions, he screamed at his opponent to stand and trade punches.
Cotto, however, stuck with his game plan of boxing behind a stiff left-jab and left-hooks, unleashing flurries and then moving out of range. By the ninth round, Mayorga's right eye was swollen almost shut by the champion's effective left hand.
Mayorga did have his moments, particularly in the seventh-round, when he was able to catch Cotto with several hard punches that threatened to turn the momentum of the fight.
"As a man, I have to admit when I do well and when I do not do so well," Mayorga said. "Give Cotto credit. He hits hard and is a great champion."
