Oleksandr Usyk has vacated the IBF heavyweight world title, which will now be at stake for his two former foes.

Dubois, who won the IBF ‘interim’ belt in his win over Filip Hrgovic at the start of this month, has now been upgraded to become the full champion.

This makes him a legitimate heavyweight world champion for the first time in his career and also opens up a door for AJ.

Joshua is already a two-time champ and now has the opportunity to make history.

If he wins on September 21, he will become just the sixth three-time heavyweight world champion in boxing history.

The first was Muhammad Ali, who beat the likes of Sonny Liston, Joe Frazier, George Foreman, Ken Norton and Leon Spinks in his truly legendary career.

Next was Michael Moorer, who moved up from light-heavyweight and claimed the lesser-recognised (at the time) WBO belt before beating Evander Holyfield for the WBA and IBF crowns. He later won the IBF again following a defeat to George Foreman.

Holyfield remarkably surpassed Moorer though, beating him in their rematch and going on to become the only four-time heavyweight world champion in boxing history with two wins over Mike Tyson. He was also undisputed king at both cruiserweight and heavyweight.

Lennox Lewis ended Holyfield’s third reign though as he crowned himself undisputed champion on his way to becoming a three-time heavyweight champion himself. He bounced back from defeats to Oliver McCall and Hasim Rahman, beating both men in rematches to regain his belts, and also toppled Tyson.

Source – Anthony Joshua vs Daniel Dubois officially confirmed as AJ attempts to join Muhammad Ali and Lennox Lewis in exclusive elite club | talkSPORT