Daniel Dubois promised to become the “king slayer” after it was confirmed he will face Anthony Joshua for the IBF heavyweight belt on September 21.

The fight at Wembley was announced on Wednesday following the confirmation by current title holder Oleksandr Usyk that he will vacate the world title.

The Ukrainian became the first heavyweight to hold the IBF, WBO, WBA and WBC belts when he defeated Tyson Fury in Saudi Arabia last month but was set to be stripped of the IBF title, with the body stipulating he must face its mandatory challenger Dubois in order to retain it.

That has opened the door for the two Brits to face off and Dubois – who beat Filip Hrgovic to become interim IBF champion earlier in June – said he will be looking to dethrone the two-time world champion Joshua.

“That’s just where I’m aiming for, to be the best,” he said. “To fight the best and beat the best. AJ has been the king for a long time.

“We all know he’s been the king for a very long time. On the night, I need to become the king slayer. That’s my goal, that’s the mission I have.

“I’m ready to let my fists do the talking. A hundred percent ready to go, train like a beast. So bring it on.

“Definitely I’m learning more about myself, as a fighter, as a person. Coming out the darkness into the light, being the man of the future, improving all round as a fighter. Really up for this, ready to go.”

Joshua was beaten twice by Usyk in 2021 and 2022 – the Ukrainian knocked out Dubois last year – but is currently on a four-fight winning run, enjoying three stoppages in his last three outings.

It will be his fourth appearance at Wembley, though his opponent will be stepping out as a main event at the national stadium for the first time.

“Congratulations to Daniel for winning his last fight (against Hrgovic), I went to watch it live,” said Joshua.

“It was a good fight between the two of them. I picked Dubois to win as well, I watch boxing closely and I picked him before.

“He came through and we are here. I’ve been having Dubois on my mind for a while. He’ll be on my mind for the next 12 weeks until I’ve got my hand raised.”

Joshua, 34, was asked whether the age gap to the 26-year-old was on his mind ahead of the bout.

“I feel fresh,” he said. “I feel good. I don’t drink, I don’t smoke. That’s about it, that’s my only vice, socialising. I don’t get caught up in antics outside boxing. I use boxing to keep me on the straight and narrow.

“Young fighters coming up, look after your bodies, look after your minds.”

Usyk had previously requested that he not be stripped of the IBF belt so that he might still hold the title when he meets Tyson Fury in December.

“Anthony and Daniel, I know the IBF title is important to you. It is my present to you on 21 September,” he said in a video posted on social media.