Derek Chisora and his manager David Haye have announced that they will amicably part ways.
The former enemies and opponents have been a partnership over the past three years, with Haye acting as Chisora's manager and assisting him in the gym.
Chisora won three fights under Haye's stewardship, including a big stoppage of David Price.
But he was knocked out by Dillian Whyte and, in the past year, has slipped to points defeats to Oleksandr Usyk and Joseph Parker, both of which he disputed.
Haye said: "It's been an action-packed couple of years, getting Derek back in the mix of the heavyweight division, taking him from 'Del Boy' to 'WAR' mode.
"When we announced our unlikely partnership we pledged to give fight fans the big nights of heavyweight clashes they have called out for and that I believe we have achieved.
"Whilst I will no longer be managing Derek, I will naturally continue to follow and support his career with great interest.
"The UK remains at the epicentre of the heavyweight division and Derek stands ready to go toe to toe with them all. 2021 is looking very exciting for him with a number of options available."
Chisora said: "Everyone close to me thought I was crazy when I told them I wanted David to manage me, but in the last two and a half years my performances in the ring have spoken for themselves.
"Giving fight fans the battles they wanted to see even when COVID put a handbrake on everything. I may have been robbed against both Usyk and Parker but have developed as a fighter. 2021 is looking very interesting, I am back in camp, ready to go this autumn. It's time for WAR.
"I would like to thank David for his support (at times patience...) and guidance during our time working together."
Haye and Chisora notoriously brawled at a Munich press conference before colliding inside the ring in 2012 in a heated grudge match which Haye won.
Chisora, now 37, is on the lookout for his latest reinvention in the heavyweight division.