Gennady Golovkin beats Vanes Martirosyan for record-equalling 20th title defence
Gennady Golovkin claimed a record-equalling 20th consecutive world middleweight title defence by knocking out American Vanes Martirosyan.
Golovkin, 36, retained his WBA and WBC belts with a comfortable second-round victory in California on Saturday.
Martirosyan was a last-minute replacement following the cancellation of the Kazakh's much anticipated rematch with Canelo Alvarez of Mexico.
"The second round it was true business," said Golovkin.
Golovkin, who is the sport's longest-reigning current world titleholder, is now unbeaten in 39 fights, including 34 by knockout. With Saturday's victory, he joins American Bernard Hopkins for the division record of 20 successful title defences.
The Golovkin v Alverez match was cancelled because of the 27-year-old Mexican's two failed drug tests in February, followed by his suspension by the Nevada State Athletic Commission on 18 April. Alvarez will be free to fight once his suspension ends in August.
The 31-year-old American Martirosyan, who normally fights at light-middleweight, said: "It was like being hit by a train.
"That is the hardest puncher I have ever faced. He surprised me with his power. He is a hell of a fighter."