Amir Khan went down to a shock points defeat by Lamont Peterson to lose his WBA and IBF light-welterweight titles in a pulsating fight in Washington DC.
Two points deducted from Khan for pushing proved crucial as the judges scored the fight at 113-112, 113-112, 110-115 in favour of the local fighter.
The Briton knocked Peterson down in the first round, but the American launched huge attacks in the third and seventh.
Khan recovered, but the second lost point in the final round was decisive.
Amir Khan calls decision 'disgusting' after Peterson defeat
"It was like I was against two people in there - the referee and Lamont himself," complained Khan immediately after the decision.
"Every time he was coming into me he kept putting his head low. I was the cleaner fighter - he was so wild in there.
"I had to push him away because his head was coming so low."
Talk before the fight centred around the 25-year-old
Khan's desire to move up to welterweight,
with the Bolton fighter frustrated in his attempts to secure light-welterweight unification bouts with WBC champion Timothy Bradley and WBO title-holder Erik Morales.
The former Olympic silver medallist has spoken of his wish to meet Floyd Mayweather at 147lbs but those hopes now seem set to be placed on hold after this demoralising defeat.
Twice Peterson, 27, hit the canvas in the first round, initially after taking a left when appearing to have slipped, then after a lightning combination from Khan which drew the referee's count.
But that would be the last time that Khan would use his superior speed to such effect as, from the third round onwards, Peterson succeeded in cutting the distance between the fighters and took advantage of his greater power.
Khan's response was to go toe-to-toe with the home-town challenger, but too often was forced to retreat as Peterson played the aggressor.
“When you go to someone's home town you don't want to allow the fight to be close, and Amir made the fight close. I think anyone who has fought Amir Khan will agree with the point deductions, he is never warned for pushing the head down or pushing you off. The points deduction did cost Khan but I don't think the fight should be marred by that, you have to give Lamont Peterson credit”
The champion recovered and, even though he hit the canvas after slipping in the fifth, he had the better of that and the following round.
Back came Peterson, catching Khan on the ropes with right and left hooks, and it was to get worse for Khan as he was deducted his first point.
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