He got back to his feet but not for long as an onslaught of punches from the champion led referee Steve Gray to intervene one minute and 59 seconds into the round and give Joshua his 21st win by knockout.
“Povetkin is a very tough challenger, he proved that tonight with good left hooks and counter punches,” Joshua said from inside in the ring.
“I came in here to have fun, and give it my best, I knew he was strong to the head but weak to the body. I was just mixing it up.
“It could have been seven, maybe nine, maybe 12 rounds to get him out of there. But the ultimate aim was to be victorious.
“I got my knockout streak back,” he added, having been taken to 12 rounds for the first time in his previous fight against New Zealand’s Joseph Parker in Cardiff in April.
The fight is the first of a two-match deal Joshua has agreed to stage at Wembley Stadium, with the second due to take place in April next year.
However, his plan to become the undisputed world heavyweight champion may have to wait a little longer as WBC title holder Deontay Wilder announced earlier on Saturday a showdown with Joshua’s compatriot and former world champion Tyson Fury on Dec. 1 in the United States.