LONDON (AP) — After a contested fight, American Lamont Peterson believes he will only receive full credit for beating Amir Khan if he repeats the feat in their upcoming rematch.

Khan lost his WBA and IBF belts in a split-decision loss to Peterson on Dec. 10, but was granted a rematch at Mandalay Bay Events Center in Las Vegas on May 19 after complaining about the referee’s decision to deduct him two points for pushing. He was also upset at the presence of an unauthorised man at ringside seen distracting an official.

Khan (26-2, with 18 knockouts) is not the only one feeling a sense of injustice.

Claims that Peterson isn’t a legitimate champion because of the perceived shadowy events that transpired in Washington, D.C., has also left him feeling aggrieved.

Asked if the aggressive complaints of Khan and his promoters took the gloss off his win, the light-welterweight champion Peterson said: “Of course it did.

But I’m a big boy, I’m a man. I’ll get over it. That’s the way I look at life.”

Peterson (30-1-1, with 15 KOs) was in London with Khan on Tuesday for the official announcement of their rematch.

Revenge was in the air for the British challenger, who said it “still hurts me seeing what went on” when he watches videos of the first fight.

A relaxed Peterson said Khan needs to quit complaining.

“I can only say that nothing shady happened in D.C. But I’m pretty sure they won’t take my word for it,” said the 28-year-old who resides there.

“To me, he has to accept he’s not the champ any more. He’s said many times he’ll train like a challenger,” he added. “You are the challenger, so you will train like a challenger. To me, he just hasn’t accepted it yet. But he’ll have to because he can’t go in the record books and change the loss to a victory.”

Khan acknowledged he underperformed in his loss to Peterson, but vows to make amends.

“I made a few mistakes in the first fight but I still felt I won it,” said Khan, who will head to the Philippines next month for high-altitude training. “It was tough, and the next one will be even tougher because we know what to expect from each other.

“We’ll see a different Amir Khan for this fight. I’ll be explosive and maybe this fight can be one of the fights of the year, too.”

Khan also is eager to start improving Britain’s reputation in the boxing world after the ugly brawl between David Haye and Dereck Chisora following Chisora’s loss to Vitali Klitschko in a world heavyweight title fight last month.

“Boxing in Britain has not been in the best light, especially with what happened,” Khan said. “You won’t ever see me do anything like that. You just don’t need that in boxing.”