With a letter sent to the World Boxing Organisation, Oleksandr Usyk elevated Fabio Wardley to world champion.
The Ukrainian informed the sanctioning body that he would not fulfil his mandatory obligation to fight Wardley and would be vacating his title.
It is the second time that Usyk's undisputed status has ended due to boxing's politics.
He became the first four-belt undisputed heavyweight champion when beating Tyson Fury in May 2024, only to give up the IBF strap.
That was claimed by Daniel Dubois, who Usyk then beat in July this year to reclaim his full set of world titles and become a two-time undisputed champion.
Wardley's fight with Joseph Parker last month had been billed as one that would guarantee the winner a shot at Usyk next for all the belts.
However, Usyk has opted against fighting Wardley next and has "elected to relinquish his title after thoughtful consideration". He still holds the WBA, WBC and IBF straps.
Alex Krassyuk, Usyk's long-term promoter until they split in the summer, has urged the 38-year-old to retire from the sport on top. Usyk, though, recently insisted he would fight until he is 41.
He has been dealing with a back injury in recent months, which saw him postpone talks with Parker after being ordered to fight him earlier this year.
Who Usyk returns to face in 2026 is far from clear.
Kubrat Pulev is the WBA regular champion, though he has a fight against Murat Gassiev next month. Moses Itauma is the number one contender but Usyk has dismissed the possibility of fighting the 20-year-old next.
On the IBF side, Derek Chisora is the highest-ranked challenger. Usyk has already fought the 41-year-old, and there would be no appetite for a rematch.
A more appealing bout would be Usyk taking on WBC interim champion Agit Kabayel. However, that is unlikely to generate the kind of purse and interest Usyk would be looking for at this stage of his career.
The two biggest fights for Usyk would be third showdowns with Anthony Joshua and Tyson Fury, both of whom have been beaten twice by the Ukrainian.
Neither of those look realistic opponents for the near future. Fury is still officially retired and has not fought since losing to Usyk in December last year, even if there is talk of him fighting Joshua next year.
Usyk’s advisor Serhii Lapi has also questioned what demand there is for a trilogy with Fury.
”Theoretically, it’s an interesting option, but for whom?” Lapin asked. “If boxing fans truly support it, then maybe. However, in my opinion, that chapter is already closed.”
Joshua, meanwhile, recently trained in Usyk's set-up and Eddie Hearn said the heavyweight was "undecided" on whether to permanently join the Ukrainian's team.
Joshua will fight Jake Paul next month in a lucrative eight-round bout. That will be his first fight since losing to Dubois more than a year ago and a third shot at Usyk is one that would be hard to justify.
Usyk has hinted he too could take on Paul, declaring in September that he wanted an MMA showdown with the American.
He said: "Soon, I'll close the book on boxing, and after that, I'll be waiting for you in the cage. Let’s see if you’ve got the balls or just a hunger for hype."
That followed Lapin in August indicating a bout of that nature could take place in 2026.
“We’re not talking about a boxing match with Oleksandr Usyk," Lapin said.
"No disrespect to Jake, but in MMA, the chances are more even. Jake has some experience, while Oleksandr would have to adapt quickly.
“This could become a massive show with a huge global audience. Talks are already underway, and if everything lines up, the fight could happen early next year."
Usyk has nothing left to prove and it would be fitting for a true great to retire undefeated. Should he continue, expect it to be money over mandatories.
