Amir Khan’s shot at Terence Crawford’s WBO world welterweight championship ended in controversial circumstances when he was pulled out by his corner after a low blow.
Khan, floored in the opening round, was declared unable to continue after being hit below the belt 47 seconds into the sixth round.
Speaking after the fight, he said: “I couldn't continue as the pain was too much.”
Crawford was dominating proceedings and was ahead on all three scorecards when the fight was stopped.
The pound-for-pound contender remains unbeaten in 35 fights, while the defeat is the fifth of Khan’s career.
Crawford vs Khan: Fight report
Khan asserted himself in centre-ring in the opening stages, backing up the switch-hitting Crawford who elected to employ an orthodox stance.
Giving up a reach advantage to his opponent, Khan exhibited his famed slick footwork without landing any punches of note, but as soon as he looked to have earned Crawford’s respect, he was caught with a vicious right hand followed by a sharp left that saw him hit the canvas.
Crawford, who has a reputation as a slow starter, unleashed a barrage of shots after the Brit made the count and nearly floored him for a second time but Khan managed to resist the Nebraskan’s advances and see out the round.
An understandably defensive Khan emerged for the second round.
He returned to his fundamentals of boxing and moving, attempting to pick off Crawford with the jab.
After a nightmare opening round, Khan looked relatively assured and he struck with a lead left hook that caught that champion flush. Enough to win the round for Khan.
Crawford adopted a defensive approach in the third, switching to a southpaw stance.
The Bolton fighter landed with a sharp right hand and he successfully kept Crawford at arm’s length for the duration of the round.
Another round in the bank for Khan, and the challenger was beginning to make inroads into Crawford’s early scorecard lead.
Just as Khan looked to be dictating the rhythm of the contest, the aggravated champion followed up a left hook with a thudding counter right that left Khan reeling.
Content to sit on the back foot in the second and third rounds, Crawford exhibited a devastating burst of speed and power in the fourth which left Khan seriously hurt.
The former unified light-welterweight world champion relied on his speed to see the round through, but the incessant barrage of body shots looked to have taken its toll on the 32-year-old.
Looking every inch a pound-for-pound contender, the WBO world welterweight champion was landing at will – notably with a left hand that caught Khan on the chin in the closing moments.
The Omaha fighter was composed unlike his jaded opponent who was rushing his work. Khan hit back with a few lead left hands, but he was being broken down by his peerless counterpart.
The fight was called off in controversial circumstances in the sixth round after Khan was caught with a low blow with 47 seconds gone.
The rules stipulate that Khan could have up to five minutes to recover, but after a brief discussion with trainer Virgil Hunter, referee David Fields was ordered to call a halt to the contest.
Confusion reigned as delegates entered the ring with some suggestions that Crawford may be disqualified for an intentional low blow.
However, Khan’s corner informed the referee that he won’t be able to continue, and Crawford was declared the winner by TKO.
The judges had it 49-45 50-44 49-45 in favour of Crawford at the time of the stoppage.
Crawford vs Khan: Post-fight interviews
Crawford: “I seen Amir Khan’s face, and he was shaking his head and I was getting disappointed because I knew that he was looking for a way out.
“Not the way that I would have liked to finish the fight. But Virgil [Hunter] is in his corner for a reason and that’s to look out for his fighter. He felt that his fighter didn’t want to fight anymore so he stopped the fight.
“There's only one fight they talk about and that's Errol Spence. Whenever he's ready I'm here.
“I can't put a gun to a promoter's head and make them make the fight. All I can do is fight everyone in front of me and we make it happen sooner or later.”
Khan: “The fight was going well. I was getting caught but catching him with some. I got hit with a shot beside my cup. The pain went down my legs.
“Virgil [Hunter] asked me how I feel, I couldn't continue as the pain was too much.
“I have had some problems in my right arm. I'm not complaining about it but was getting some sharp pain. He caught me with a great shot early in the fight.
“I knew the mistake I made. I was trying too hard. He's better than I thought. He's quick, sharp, a great fighter.
“I want to apologise to everybody. I tried.”
Crawford vs Khan: Undercard results
Lightweight sensation Teofimo Lopez knocked out Edis Tatli in the fifth round in the chief support. The Ring magazine Prospect of the Year finished the contest with a vicious right hand to the body.
Lopez imposed himself after an intriguing opening which saw both fighters exchange jabs, and the 21-year-old has moved a step closer to unified world champion Vasyl Lomachenko after the 13th win of his career.
The Honduran-American asserted his dominance in the fourth round before flooring the seasoned Finn midway through the fifth – the first knockout defeat of his career. ‘The takeover is here’ declared one of the sport’s most exciting prospects after another impressive display.
Highly touted American and fellow lightweight Shakur Stevenson dominated Christopher Diaz to claim the biggest win of his career in New York.
The 2016 Olympic silver medallist cruised to a points victory, winning 100-90, 99-91, and 98-92 on the scorecards.
The 21-year-old southpaw, who is managed by former pound-for-pound king Andre Ward, showcased his superior hand speed and footwork in a one-sided contest against the former WBO super featherweight world title challenger, and the 11-fight novice is now on the brink of world level.
After the bout, the self-proclaimed ‘new Mayweather’ re-iterated his desire to challenge IBF featherweight world champion Josh Warrington.
Lightweight Felix Verdejo laboured to a ten round unanimous decision victory over Costa Rica’s Bryan Vasquez. Verdejo, 25, suffered defeat in his last visit to Madison Square Garden against Mexico’s Antonio Lozada 13 months ago, but he avenged the only defeat on his record in an uninspiring contest against 31-year-old Vasquez.
Verdejo won 98-92, 97-93 and 97-93 on the scorecards and the Puerto Rican, compared to legendary compatriot Miguel Cotto by promotor Bob Arum, will be eyeing up mega-fights with Lomachenko and Lopez after the 25th win of his career.
Elsewhere, there were victories for Carlos Adames, Lawrence Newton, Vikas Krishan and Edgar Berlanga.
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