NEW YORK (AP) Vasyl Lomachenko doesn't just beat fighters. He makes them quit.
Even Guillermo Rigondeaux, who had never even lost a fight as a pro.
''I guess I should change my name now to NoMaschenko,'' Lomachenko said.
Lomachenko won their bout Saturday night when Rigondeaux's corner stopped the fight after six rounds because the boxer was complaining of pain in his left hand.
Lomachenko was easily winning boxing's first pro match between two-time Olympic gold medalists when Rigondeaux and his trainers jointly called for the match to be stopped.
Promoter Dino Duva said Rigondeaux first felt pain in the second round and hurt it more significantly in the third. Duva said doctors believed the hand could be broken and were sending the 2000 and 2004 Olympic gold medalist from Cuba to the hospital for X-rays.
Duva said the injury came from a punch - though Rigondeaux certainly didn't hit Lomachenko with many of them.
''Where did he hurt his hand, in the dressing room?'' promoter Bob Arum said.
Lomachenko (10-1, 8 KOs) earned his seventh straight victory by stoppage and defended his WBO 130-pound title. And for the fourth straight time, his match ended with his opponent quitting.
Rigondeaux lost for the first time in his 18 pro fights and was loudly booed afterward by a crowd that was supporting both fighters early in the match.
But it was quickly apparent that the 2008 and 2012 gold medalist was too much for the 37-year-old Rigondeaux, the 122-pound champion who was moving up two weight classes for the historic match.
''I adjusted to his style, low blows and all,'' Lomachenko said.
Long one of boxing's best defensive fighters, even Rigondeaux couldn't find a way to defend himself against Lomachenko's onslaught.
''It just amazes me what this guy does to an opponent,'' Duva said. ''He just frustrates his opponent so bad you don't even know what to do.''
Lomachenko started cautiously but by the third round he had begun finding his way through Rigondeaux's defense.
He was leading 59-54 on two judges' cards and 60-53 on the other, and a fighter who does as little offensively as Rigondeaux was unlikely to make that up even if he could've continued.
''I'm going to come back and fight against anybody because there are no excuses,'' Rigondeaux said through a translator.
Rigondeaux would have liked the fight at a lower weight but the height difference may have been a bigger problem. Giving up three inches to the 5-foot-7 Lomachenko, he frequently was caught when he tried to lunge forward for shots and couldn't slip Lomachenko's accurate punches, and when he kept trying to duck lower and lower Lomachenko even hit him on top of the head.
It was tense in the fifth round, when Rigondeaux was warned for hitting on the break and they jawed at each other after the bell sounded to end the round. But Lomachenko came back and scored with some solid shots in the sixth, and it became a bigger round for him when Rigondeaux had a point deducted for holding.
Moments later, it was over.
Lomachenko won titles in two weight classes after just seven fights and it may not be long until he has a chance at another, possibly moving up to lightweight next year.
Former Olympic medalists Shakur Stevenson and Michael Conlan were among the winners on the undercard. Stevenson (4-0, 2 KOs) outclassed Oscar Mendoza (4-3) before referee Sparkle Lee stopped the featherweight bout midway through the second round. Fighting near his hometown of Newark, New Jersey, the southpaw who won silver in 2016 landed sometimes three or four punches in rapid succession before Mendoza could get out of the way.
Conlan (5-0) delighted the contingent of Irish flag-waving fans with a unanimous decision victory over Argentina's Luis Molina (4-4-1), winning every round of the six-round bout in his first pro victory that didn't come by stoppage.
Conlan peppered Molina with combinations to the body and left uppercuts to the chin in the arena where he made his professional debut last year on St. Patrick's Day. Arum also plans to have the 2012 bronze medalist from Belfast fight again next year on the March 17 holiday.