Tyson Fury and Oleksandr Usyk have finally agreed terms on an era-defining undisputed heavyweight clash which will take place in Riyadh, Saudi Arabia.

A date has yet to be officially announced but Fury's representatives Queensbury Promotions — managed by Frank Warren — confirmed papers have been signed, with December or January thought to be the likeliest possibilities.

Lineal champ Fury, 35, holds the WBC belt while his Ukrainian opponent Usyk, 36, is the WBA (Super), WBO and IBF king, with all the gold set to be on the line for the first time in the four-belt era.

Promoter Warren, 71, said: "Delighted to finally get this fight signed. This is the biggest fight that could possibly be made in our sport.

"The heavyweights always spark the imagination of the fans and I have no doubt this will be the biggest boxing event of the century.

"I look forward to Tyson reclaiming the three belts that he never lost in the ring. Huge thanks to His Excellency [Turki Alalshikh] and the GEA [General Entertainment Authority]."

Long time coming

The surprise announcement comes after several previous attempts to square the undefeated duo against each other had drawn dead.

Fury must first come through a non-title bout with MMA star Francis Ngannou on October 28 — a clash also taking place in the Saudi Arabian capital.

Meanwhile, Usyk was last in action five weeks ago when stopping Fury's fellow Brit Daniel Dubois in the ninth round having survived a contentious low blow earlier in the contest.

His Excellency Turki Alalshikh said: "This is the fight that everyone has wanted to see for some time and now it is finally happening — the world's two heavyweight champions going into the ring against one another. 

"It is the biggest fight in boxing, the world will be watching and we are so proud to be the hosts for this spectacle."

Alexander Krassyuk, Usyk's promoter, added: "I can't believe that it’s happening but it is.

"Difficult to express my admiration for being part of the biggest heavyweight fight of the century."