Bernard Hopkins, right, and Chad Dawson fight in the second round of their light heavyweight boxing match at Staples Center on Saturday night. (Jae Hong / Associated Press )

Hopkins squared off with former champion Chad Dawson on Saturday in the main event at Staples Center in an attempt to defend the belt he won from Pascal.

But the ending was almost as bizarre as the one last month when Floyd Mayweather Jr. knocked out Victor Ortiz when he wasn't looking.

In this one, Hopkins and Dawson had been holding a lot during the first two rounds. In the second, Dawson lifted Hopkins off his feet with his shoulder after Hopkins had leaned into him. Hopkins went down hard to the canvas and onto the apron.

Hopkins, claiming a shoulder injury, was unable to continue and Dawson was credited with a second-round knockout before 8,431, taking Hopkins' title in the process.

After Hopkins (52-6-2) was put on a stool in the ring, Dawson came over and started yelling at him. Hopkins stood up and yelled back.

Referee Pat Russell claimed there was no foul, thus the KO victory for Dawson.

"They set me up," Hopkins said. "It should have been a no-contest.

The guy (Russell) asked me if I could continue and I said, `Yes, with one arm.' And then he called the fight.

"He picked up my two legs off the ground and he threw me down on my shoulder. I have a knot.

"But I said I would continue with one arm. I was ready. He didn't say he was stopping the fight. He just walked away. ...

"That was a blatant foul and it should have been a no-contest."

Said Russell: "He could not continue because of an injury. No foul."

George Dodd, executive officer of the California State Athletic Commission, backed Russell.

"The referee did not call the foul," he said. "He couldn't continue and so it was a TKO (actually a KO) for now. At this time, that's the call."

Dawson (31-1, 18 KOs) was booed heartily by the fans in attendance. He showed complete disdain for Hopkins in a post-fight interview.

"I'm sorry for the disappointment for the fans," said Dawson, 29.

"He ran from me for three years. I know he didn't want the fight. He keeps talking about Philly and being a a gangster.

He's no gangster. Gangsters don't quit. He's a weak mentally and physically minded person. I was going to get on him and he knew it. He jumped on me and was pulling me down.

"I pushed him off with my shoulder."

Jorge Linares of Venezuela was trying to win a title in his third weight class when he stepped into the ring against Antonio DeMarco of Mexico in the semi-main event. But DeMarco foiled that plan when he stopped a bloodied Linares at 2:32 of the 11th round to win a vacant lightweight championship.