Chinese giant Zhilei Zhang scored the biggest win of his career and a heavyweight upset stopping Joe Joyce in six rounds in front of a shell-shocked crowd at the Copper Box Arena in London.

Zhang was imperious, landing at will from the start until Joyce’s right eye swelled shut and caused the intervention of referee Howard Foster after 1-23 of the sixth round.

Joyce had very little answer to Zhang’s long, raking left hand from the opening bell in a battle of Olympic silver medallists, Zhang at the 2008 Olympics and Joyce at the 2016 Games.

Zhang earned the WBO interim heavyweight title with the win.

“Today is mine,” said Zhang. “It belongs to everyone who showed up and every Chinese who showed up. I’m 39-years-old but I’m disciplined, I train hard and next I’m going for the title.”

“I’m disappointed with my performance,” Joyce admitted. “I couldn’t get out of the way of the left hand. I hadn’t fought a southpaw in so long, I could have done better, I gave it my all, I expected to win like I always do. He hits hard and he’s got an awkward style and he’s a powerful southpaw at that. I’ll be back. My journey is not over. This is just a hurdle. I’ll be back.”

The exceptional Zhang started to land big shots after about 90 seconds and the southpaw from China had no trouble finding the target with his long left hand. Joyce had been looking to fire off straight right hands, but Zhang was wise to them and moved out of range without taking too many. The first was a good round for the visitor and Joyce looked somewhat startled by Zhang’s fine start.

It got worse for Joyce in the next and he was wobbled by a straight left halfway through the second, and Joyce’s head was jolted back several times. The pre-fight favourite was getting busted up and bled from the nose, Zhang was looking impressive although near the end of the session Joyce started to get busy and while Joyce’s shots did not appear to have the power that Zhang’s did, he started to increase the volume.

Both are 6ft 6in but Zhang, who outweighed Joyce by 13lbs, looked the much larger man although Joyce’s mobility and punch output became more of a factor in the third as he tried to claw his way back into the fight.

One wondered whether Zhang, almost 40-years-old, could maintain the pace, but Joyce’s right eye was closing and his head was being jarred back with alarming regularity.

A right hand from Joyce in the fourth bought him momentary respite in an increasingly punishing affair and there was savage two-way action as they battled through the next. Joyce had success in close but he was staying in the pocket too long and getting caught, his right eye bulging, swelling and turning purple.

Meanwhile, Zhang was looking composed and fit.

In Joyce’s corner, Jimmy Tibbs went to work on the damaged optic and Joyce survived a doctor’s inspection to start the sixth but it seemed he was running out of time and also he was still unable to get out of the way of Zhang’s left hand as the eye worsened.

Joyce was tough but soaking up left hand after left hand and, midway through the sixth session, the doctor was asked to look at the eye again and this time referee Howard Foster waved it off and Joyce’s unbeaten record was gone and The Juggernaut’s career momentum has been snapped.

Zhang has never looked better. Queensberry’s George Warren said there was a rematch clause and that they now have options on Zhang.

Putney’s Joyce is 15-1 (14), Zhang is now 25-1-1 (20).

On the undercard, Mikaela Mayer won a comfortable 10-round decision over late substitute Lucy Wildheart, from Sweden.

Wildheart came in for Christina Linardatou a day ago after the latter failed a medical.

Mayer, who worked the body well throughout, won the WBC’s interim lightweight title and was victorious by margins of 100-90, 98-91 and 98-92.

Heavyweight hope Moses Itauma is now 3-0 (2 KOs) but he was made to go the distance for the first time winning all six rounds against the spirited Kostiantyn Dovbyshchenko. Itauma showed good variety and poise banking six invaluable rounds after the first two contests of his career failed to last a total of one minute. Itauma is only 18 and definitely one to watch,

London middleweight contender Denzel Bentley took just 45 seconds to dismiss Scottish southpaw Kieran Smith in his first fight since he was outscored by WBO champion Kazakh Janibek Alimkhanuly. Smith began unravelling from a left hook, took a right to the body and then was downed by a heavy right hook.

“I’m just happy he’s okay,” said Bentley, who is now 18-2-1 (15 KOs). Smith drops to 18-2 (7).

Commonwealth lightweight champion Sam Noakes saw off Kathik Sathish Kumar in two rounds, dropping the previously-undefeated Indian in the first and second. Both were 10-0 at the first bell.