Helenius received medical attention and some oxygen before getting back on his feet. Photo: Reuters

Former heavyweight world champion Anthony Joshua beat Finnish stand-in Robert Helenius with a seventh round single-punch knockout to keep himself on track for a lucrative payday against American Deontay Wilder next year.

Helenius, stepping in after Britain's Dillian Whyte was ruled out of the non-title fight by a dope test a week ago, lasted longer than expected but crashed to the canvas one minute and 27 seconds into the round on Saturday.

Some of the crowd at London's 02, who had grown restless with some booing already in the third round, were heading for the exit by then as Joshua failed to deliver immediate fireworks.

Joshua looked nervous and stiff at the start and strangely tentative when Helenius, who fought in Finland only a week ago, appeared to be out on his legs and ready for the taking.

Crowd impatience

He climbed straight out of the ring without saying a word after referee Victor Loughlin stopped the contest.

He then fist-bumped fans, stopping to share a swig of a drink with watching former UFC champion Conor McGregor, before stepping back inside the ropes.

The knockout was the 23rd of Joshua's career, taking his record to 26 wins and three defeats. Photo: Reuters

Helenius meanwhile received medical attention and some oxygen before getting back on his feet.

"I knew this would happen, everyone's talking about the new AJ and the old AJ and after two or three rounds the crowd starts to get a little bit impatient," Joshua's promoter Eddie Hearn told the media.

"He finds the measure of his right hand and he delivers one of the knockouts of the year on Robert Helenius... this is just the AJ you're going to see now.

Hard to get up

"He's still got to be more aggressive than we saw tonight but there's a lot on the line."

The knockout was the 23rd of Joshua's career, taking his record to 26 wins and three defeats, but his first since December 2020 when he beat Bulgarian Kubrat Pulev in a WBA, IBO, IBF and WBO title defence in London.

Joshua lost those belts to Ukraine's Oleksandr Usyk in September 2021.

There has been talk of Joshua fighting Wilder, the former WBC champion, next year but the Briton needs to keep winning to be talked about in the same breath as the American and reigning champion Tyson Fury.

"It's hard for him to get up for fights like this," said Hearn. "The Wilder fights, the Fury fights, that's what he wants."

Reuters