The Russian started quickly, bloodying the champion’s nose, reinjuring the body part Joshua said had been softened up by Carlos Takam two fights ago.
“I can take a lot, no doubt about that,” Joshua said of absorbing punishment at the post-fight presser.
“But at heavyweight all it takes is one wrong punch. I didn’t take too much because I was keeping it long but for sure he knows how to punch.
“It’s a nice way to wake up and realise you’re in a tough fight.”
Povetkin, who was absent from the post-fight press conference, came out firing and posed Joshua problems in the early going.
Asked whether he was expecting that start, Joshua said: “When they’ve got a chance of capturing these belts it goes down to their heart.
“I know how to dig deep, he’s tough but I knew how to break him down.”
Both Joshua and promoter Eddie Hearn said they wanted Deontay Wilder in the opposite corner in April. Hearn commented that Wilder had a rematch clause against Fury, so if Wilder lost on December 1 to the Englishman then it takes him out of fighting Joshua in Wembley in April.
“Good luck to them both,” Joshua said of Wilder-Fury. “Boxing needs it. April 13 is booked for whoever wants to step up and take the challenge.”
Hearn continued: “In terms of who I want to win for AJ, it’s Wilder, because that’s the biggest fight in world boxing.”
Then AJ was directly asked: “Is it Wilder you want in April?”
“Yes,” he confirmed, adding, “If Wilder’s not serious, there’s other fighters out there.”
Joshua-Wilder would be the biggest fight in British boxing history, Hearn added.
“AJ’s fight with Klitschko was the biggest fight ever in this country, this one would eclipse that,” he predicted.
In the corner, Robert McCracken was satisfied with Joshua’s performance and said his charge “will only get better.”
“Towards the end of the first round he held his feet and if you hold your feet you haven’t got time to defend,” he said of the Russian’s attacks.
“You’re going to get hit at this level but once Anthony slowed him down with the body and head jab it was only a matter of time. He’ll defend better next time.”
Joshua, who improved to 22-0 (21), now boasts wins over Wladimir Klitschko, Joseph Parker, Carlos Takam, Dillian Whyte and Povetkin, and he has stopped four of those five.