Dillian Whyte signed his contract to face Tyson Fury merely hours before the deadline was supposed to end.
There were concerns that Whyte may not go through with the procedure over a dispute about the 80-20 purse split in Fury’s favor.
Whyte, who holds the WBC interim title after a rematch win over Alexander Povetkin, will challenge Fury for the right to become WBC heavyweight champion.
He secured his WBC mandatory title shot after avenging his loss to Alexander Povetkin last March. Fury, meanwhile, retained his WBC belt with an 11th-round knockout of Deontay Wilder in October same year.
The winner of Dillian Whyte vs Tyson Fury could challenge for the undisputed world title, with Oleksandr Usyk set to defend his WBA, IBF, and WBO world belts against Anthony Joshua.
Whyte will be entitled to £6million from the fight after signing the contract plus an extra £3m bonus if he overcomes the unbeaten Fury.
Fury’s co-promoters Frank Warren and Bob Arum won the purse bid with a record offer of £31m, of which Whyte is entitled to 20 percent.