Amir Khan denied he had dispatched Zab Judah with a low blow to become unified light-welterweight champion.
Khan added Judah’s IBF title to his WBA belt with a fifth-round knockout in a brilliant display in front of a 7,279 crowd at the Mandalay Bay Events Centre.
But his 26th victory and second win in Las Vegas was disputed by veteran southpaw Judah, who claimed he had been hit below the belt.
Locked in a tangle, Khan spotted an opening and drove a right uppercut through the middle that landed just above the waistline of Judah’s shorts.
The American went down in agony and was counted out by referee Vic Drakulich with 13 seconds of the round remaining, resulting in jeers from his disgruntled supporters.
Replays suggested the shot was legal and Khan was content he had ended the contest legitimately.
“I don’t think it was a low blow. It was a clean shot and the referee was there,” he said.
“In my eyes it was a clean shot, just above the belt. Zab took the shot.
“It was a very hard shot and we’d been working on the shot throughout our camp.
“It happened naturally, I fired the uppercut and it worked for me.”
Judah claimed he thought Drakulich’s count was to give him time to recover from the perceived low blow and only realised his error when it was too late.
“I don’t make any excuses but that was a low shot,” he said.
“I went down and the referee was counting, I figured he was counting for a low blow – the eight count to get myself together.
“But when I heard him say ’nine, 10, it’s over’ I said, ’what do you mean it’s over, it’s a low blow’.
“We’ll have the right people take a look at it. But Khan fought a good fight.”
The controversy failed to mask the fact that Judah had been well beaten by a vastly superior opponent.
Unable to cope with Khan’s speed and aggression, the 33-year-old was dominated throughout and had begun to take significant punishment before the decisive blow was landed.
Khan had won all four previous rounds on each judge’s scorecard and he was able to reflect on one of his finest performances.
“I felt sharp. The gameplan was to keep away from Zab’s powerful back hand, so we always had to move from it and we did that well,” he said.
“Zab’s very awkward, at times I was missing him and he’s one of the quickest fighters I’ve faced.
“I still think he’s got a lot in the tank, he’ll still win a world title.”
The contest was arguably the toughest assignment of Khan’s career with five-time champion Judah having fought Floyd Mayweather, Miguel Cotto and Kostya Tszyu during a respected career.
But he controlled the fight from the start and was immediately onto the front foot, spitting out his jab without landing before connecting with a sharp left hook.
Showing more aggression, the Olympic silver medalist fired flurries of punches with the right hand his most effective shot and Judah looked fazed by his opponent’s speed.
Judah landed with a short right from his southpaw stance in the second round, jarring Khan’s head backwards, but the younger fighter hit straight back in a brief exchange.
The more experienced Judah was being bullied by Khan, who continued to advance with intent in the third.
The body was proving a happy hunting ground as Khan dominated the fourth round and swelling began to appear under Judah’s left eye.
It was one-way traffic as Judah, known as a wily and tricky operator, continued to be outboxed and he was now bleeding from the nose.
Khan was reigning down blows upon his head in the fifth round and Judah was beginning to take significant punishment with the finishing shot was delivered soon after.
Trainer Freddie Roach felt the performance was flawless.
“Amir followed the gameplan very well,” he said.
“He used the jab and took Zab’s power away from him. He won every round. He fought the perfect fight.”