Oleksandr Usyk has become the undisputed world heavyweight champion, defeating Britain's Tyson Fury after one of the great title fights in modern boxing.

Usyk won the close fight by split decision, with the judges scoring the bout 115-112 and 114-113 to Usyk, and the third scoring 114-113 for Fury.

The Ukrainian has now become the first undisputed heavyweight champion this century.

It was a back-and-forth fight between the two greats of their generation, with the ninth round proving decisive as Usyk achieved the only knockdown of the fight. 

Arguably, referee Mark Nelson could have stopped the fight, such was the damage Fury had taken. 

The Ukrainian nailed multiple left hooks which had Fury wobbling and on the verge of falling to the canvas. 

He collapsed into the corner, with the referee declaring a corner knockdown.

Usyk, with tears in his eyes, thanked his team and his country, Ukraine, which is at war with Russia.

Fury, who controlled multiple rounds, said he thought he should have been declared the winner. 

"Make no mistake, I won that fight in my opinion and I'll be back," he said.

"I've got a rematch clause … we [will] run it back in October."

Usyk started the fight methodically, controlling the space in the ring despite giving up an enormous reach deficit to Fury.

Shots to the body were the hallmark of Usyk's opening rounds, as Fury tried to laugh off every shot that landed.

As Fury remained trapped on the backfoot Usyk continued to score, with the southpaw's left hook landing often.

Fury was able to gain some momentum in the third round when he started landing shots to the body.

The right uppercut, particularly to the midsection, was scoring for Fury and momentarily stopping Usyk's advancements forward.

The Brit took a moment to showboat in each of the opening four rounds, seemingly excessive even for a man who is often clouded in entertainment and showmanship.