Daniel Dubois stops Filip Hrgovic as Deontay Wilder is knocked out ...

Britain's Daniel Dubois took a huge step towards heavyweight world title contention after stopping IBF mandatory challenger Filip Hrgovic in the eighth round of their fight in Riyadh on Sunday.

Referee John Latham intervened 57 seconds into the round on doctors' advice at the Kingdom Arena with the big Croatian bleeding from cuts over the eyes.

The fight was for the interim belt, which could become a world championship title if Ukraine's undisputed world champion Oleksandr Usyk relinquishes his or is stripped by the sanctioning body.

Deontay Wilder meanwhile saw his hopes of a potential showdown with Anthony Joshua fade away as he suffered a fifth-round knockout defeat to Zhilei Zhang in the night's main event.

That fight could instead now fall to Dubois, who seemingly put himself in pole position for a title fight against the former unified champion.

"I've heard the next opponent will be AJ, so bring it on," Dubois told DAZN after the outstanding performance of his career to date. "I'm anxious to become the best, this is my era and my time.

"I'm glad I've got this IBF belt and on to the next."

Promoter Frank Warren said that fight could be at London's Wembley in September.

The defeat was a professional first for Hrgovic, who now has a record of 17-1 while Dubois has 21 wins and two defeats, including a loss to Usyk in August.

Hrgovic led the opening rounds but the blood started flowing from the second round and Dubois sensed events were going his way.

The Croatian looked out on his feet in the seventh, with Dubois landing some punishing blows and adding to the damage from the cuts, but somehow made it to the bell.

"The round before the last, I was getting to him. It was just coming together like magic," said Dubois, who admitted he had taken time to warm up.

"It's all a learning experience. I've come from rock bottom last year and now were back on top."

Wilder topped the bill in what had been touted as a make-or-break moment in the latter stages of his career, a stoppage victory over Zhang seemingly required were there to be any chance of reviving of prospective meeting with Joshua later this year.

The once-destructive Bronze Bomber again, though, looked a shade of his former self, as he had done in his defeat to Joseph Parker last time out.

A tentative approach and a reluctance to let that devastating right hand fly invited Zhang forward, the 41-year-old controlling the fight before finally making the decisive breakthrough in the fifth.

Zhang first rocked Wilder off balance with a glancing right hand, before finishing the job with another thumping shot to the undefended face of the American, who went crashing to the canvas in what could spell the end for his career.

The win for Zhang marked an impressive response to his points defeat to Parker earlier this year, while ensuring that, for now, he sticks around among the division's marquee names.

"I lost to (Joseph) Parker, it was a fair loss. He was the better man that night. I've learned since then. As long as the bell doesn't ring, stay focused," said Zhang.

"I have to pretend Wilder didn't have a right hand and I successfully took it away.

"Road to the championship."