The boxing match was held on Saturday in Brentwood, Essex, and ended with Povetkin, 40, eventually knocking out Whyte.
Whyte had completely controlled the fight in the first four rounds but was downed by a left uppercut in the fifth.
"Alexander is a puncher and he only needed one chance. And he found it, bottom left, his favorite jump shot, either from the side or from the bottom. White too early, apparently, believed in his victory. He even started to play a little, opened up, and Alexander punished him for this. Alexander's blow was like a shot", former WBC champion Grigory Drozd said.
Povetkin became a mandatory challenger for the fight with the winner of the match for the WBC title between British boxer Tyson Fury and American Deontay Wilder.