It was the first time the Russian, whose only previous professional loss was a points defeat by Wladimir Klitschko, had been stopped in the paid ranks.Victory saw Joshua, the London 2012 Olympic champion, extend his unbeaten professional record to 22 wins from 22 fights, with 21 knockouts.
Povetkin showed early signs of danger by making Joshua stumble in the first round with a wicked left hook before blood poured out of the nose of the champion.
Joshua started to dictate the pace as the rounds went on before going on to overpower and knock Povetkin down to the canvas twice in the seventh round.
