Terence Crawford retained his WBO welterweight title Saturday, stopping Amir Khan in the sixth round when the Englishman was unable to continue because of an accidental low blow.
Crawford, who was making the second defence of his title, had little trouble controlling the fight and winning by a technical knockout against the overmatched Khan.
Crawford has now won nine of his last 11 fights by stoppage and Saturday's surprise ending happened after he hit Khan with a hard left to the groin 47 seconds into the sixth round at Madison Square Garden in New York.
Khan buckled and was in obvious pain as he went over to his corner. During the injury stoppage, Khan's trainer Virgil Hunter asked his boxer if he wanted to continue and Khan said no. Khan could have taken a five minute break to regain his composure but chose not to.
Three division world champion Crawford improved to 35 wins and no losses.
"The fight was just getting interesting,” Khan told BT Sport. “Terence was great, I am not taking anything away from him. I have realised why he was one of the best pound for pound. I could feel that punch in the stomach and legs. I have never been hit below the belt and was in pain.
"I could feel it in my stomach and legs. I said 'I can't move'. There was no point taking five minutes out, I could not continue."
Top Rank CEO Bob Arum, who promotes Crawford, was furious with the ending and believes Khan was looking for a way out.
"He had five minutes to recover," Arum said. "It was an accidental low blow. He could have recovered from it. They have a cup, right? But he was looking for a place to fall."
Crawford, who is considered one of the best pound-for-pound fighters in the world, sent Khan to the canvas in the first round with an overhand right followed by a left to the temple. He delivered a similar overhand punch in the last 10 seconds of the round which wobbled Khan's legs again.
The next couple of rounds saw the 146-pound Crawford throwing almost all his punches at the head of Khan. By the fourth round Crawford was in complete control and Khan's face was showing the wear of getting hit with clean punches.
For Khan, the 2004 Olympic silver medallist, it was another disappointing world title fight. He is 2-2 in his last four fights.