The heavyweights went toe-to-toe in a back and forth contest before a stunning left hook landed flush on the chin of Parker.

Joyce claimed the WBO interim heavyweight title with the biggest win of his career and now has his eyes set on challenging heavyweight champion Oleksandr Usyk in 2023.

The Briton's step up in class had been debated after 14 professional fights against lower-level opponents. He turned 37 this week having only turned pro when he was 31 after a late start to his amateur career.

But Joyce showed a granite chin to become the first man to stop Parker, a former world champion.

"Joseph Parker... what a fighter and what a fight," he said.

"It was a tough fight and praise to Parker. I really enjoyed it and I had to dig deep to get through the rounds. I hit him with everything I've got, I tried it all and he was still coming forward.

"I managed to drop him at the end but it was hard work. Usyk let's get it on."

Joyce steamrolls to victory

The fight took shape in the third round. Parker started well, using his jab and landed some heavy shots, but Joyce just kept coming forward.

He bloodied the nose of Parker in the second and the third exploded into relentless action, with both men trading punches.

Parker was rocked by a superb one-two from Joyce, seconds after the Brit had been tagged by a right hand. The Kiwi stayed on his feet, amazingly, and fought back as the ferocious head-to-head continued to the bell.

Joyce was hit again and again by Parker's big left, but stood firm each time, showing no sign he felt the force of his opponent's shots.

He responded to every one of Parker's blows with spiteful shots of his own, often big right hands or chopping short punches.

The Briton shrugged off the best Parker had to offer, hard left hooks in the fourth and a massive swinging right in the fifth.

Parker landed his best shots but Joyce kept coming forward

Joyce, perhaps feeling he could withstand whatever Parker threw at him, suddenly picked up the pace in the sixth round, trapping Parker in the corner and unloading.

Parker defended himself in front of his corner and tried to slow Joyce with body shots. But it didn't stop the onslaught.

The Olympian bloodied Parker's nose again in the seventh before opening up a big cut above his right eye.

Parker stumbled backwards under the barrage and Joyce poured forward again, but the bell arrived just in time to save the Kiwi.

Into the eighth round and Parker's eye was clearly bothering him as he repeatedly touched it. The visiting fighter looked exhausted but finally a hard left caused a reaction from Joyce.

For the first time in almost 25 minutes Joyce staggered under the weight of the shot, but the success was short-lived as he came forward again.

Parker's left landed again in the ninth round and the heavyweight stood still for a second, waiting to see if the immovable object in front of him was hurt. He was not.

With Joyce flooding forward again, Parker smashed him in the face with four short left hooks. No luck.

Joyce then came out swinging in the 11th and finally put his opponent down. Parker missed the count to bring to a close a remarkable battle.

Serrano one step closer to undisputed crown

Amanda Serrano added another world title to her collection

Amanda Serrano is the new WBO, WBC and IBF featherweight world champion after beating Sarah Mahfoud on points.

The Puerto Rican, fighting for the first time since losing to Katie Taylor in April, was levels above her Danish opponent, taking control from the first exchanges and drawing blood in the second round.

Despite her dominance, Serrano was unable to stop her game opponent, who recovered from a shaky start to see the final bell.

Serrano, 33, was clinical and spiteful in her southpaw stance, landing heavy shots throughout the 10 rounds, including some eye-catching left hooks and body shots.

Mahfoud, jittery on her feet to begin with, winced in pain as Serrano fired off at will at times, but slowly grew into the fight.

The defending IBF champion's corner did her best to patch her up between rounds, with blood streaming from her scalp.

Serrano continued to push forward, walking through Mahfoud's shots, just as she did so superbly six months ago against Taylor.

Mahfoud found success in the later rounds as Serrano's pace dropped slightly.

But Serrano was a clear winner and the 43rd victory of her career moves her one step closer to becoming the undisputed champion at featherweight.

The seven-weight world champion then hinted that fans may have to wait for the Taylor rematch.

"She gave me a fight. I want the last piece of the puzzle to become undisputed then I want the rematch with Katie Taylor," she said.