Tyson Fury has officially activated a rematch clause to fight Oleksandr Usyk, according to Top Rank CEO Bob Arum. 

The Ukrainian defeated Fury last weekend in a spilt decision victory to become the first fighter since Lennox Lewis defeated Evander Holyfield in 1999 to unify the belts.

However, Usyk was in danger of being stripped of his IBF Championship due to the fact he was meant to make a mandatory title defence against Croatia's Filip Hrgovic. 

With this in mind, IBF President Daryl Peoples confirmed that Usyk officially requested an exception to keep his IBF heavyweight world title for a Fury rematch, rather than being stripped for not facing his IBF mandatory challenger. 

Now, it appears his wish has been granted after Arum confirmed that Fury has activated a rematch clause with his Ukrainian counter-part. 

According to talkSPORT, Arum relayed the news before saying: 'That fight will take place either at the end of this year or the beginning of next year in Riyadh.' 

Hrgovic has been the top heavyweight contender since an August 2022 win over Zhilei Zhang. 

The Croatian will be in action next weekend when he takes on England's Daniel Dubois as part of the Matchroom vs. Queensberry 5-v-5 in the same Saudi Arabia venue where Usyk tasted victory last week. 

Usyk went into his titanic clash with Fury knowing that his undisputed reign could possibly last only two weeks - given the mandatory challenger. 

The threat of a short undisputed reign and splinter of the belts was always a possibility when the original date of Usyk's clash with Fury was made. 

However, it was further complicated after the pair's fight was pushed forward following the injury to Fury's eye that saw the bout moved to a later date. 

Usyk won the WBA, IBF and WBO titles in a Sept. 2021 points win over Anthony Joshua and retained the bets in a rematch against the Brit a year later - the same night Hrgovic beat Zhang to become the mandatory challenger.

Now, the 37-year-old wants to extend the run with all four belts, so he can defend them against the Gypsy King once again in their expected rematch later this year. 

Fury, meanwhile, has been handed a one-week ban from boxing following his defeat last weekend. 

It has been revealed that the UAE Boxing Commission gave him a rather meaningless one-week medical suspension which meant that he would not have been allowed to fight until this weekend.