ATLANTIC CITY, N.J. -- Argentina's Sergio Martinez retained the WBC Diamond middleweight title, stopping Englishman Darren Barker in the 11th round Saturday night at Boardwalk Hall.
Martinez (48-2-2, 27 KOs) landed a straight right that put Barker (23-1, 14 KOs) on the canvas.
Barker tried to get up after a few seconds, but was still on the ground when referee Eddie Cotton completed his 10-count at 1:29 of the round.
"I can't remember the punch," Barker said. "My legs just fell out from under me. I was trying to get up, but couldn't. I didn't feel he was a massive puncher before that."
Barker had some success early in the fight, landing some jabs and a few straight rights that broke Martinez's nose in the fourth round. But from the fifth round on, Martinez dominated the fight behind three- and four-punch flurries that left Barker covering up for most of the bout.
Through 10 rounds, judges Lynn Carter (96-94), Victor Loughlin (97-94) and Alejandro Roche (99-91) all had Martinez ahead.
"I knew it would be this kind of fight," Martinez said through an interpreter. "I planned for this. I always get a second wind. We train for that. It's part of our game plan going in. We knew we would get stronger as the fight went on. I just kept throwing right hands because I knew sooner or later they would start landing."
Martinez, who lives in Oxnard, Calif., is widely considered one of the top three pound-for-pound fighters in boxing along with welterweights Manny Pacquiao and Floyd Mayweather Jr. Martinez has been campaigning for a fight against Pacquiao or Mayweather at a catch-weight of around 150 pounds, but neither fighter appears willing to move up that far in weight.
"I'll fight anybody," Martinez said, "as long as I can come to a good deal and so can my rival."