BBC Sport looks at where Oleksandr Usyk ranks among the all-time heavyweight greats and who in the current generation could beat him.

LONDON -- Oleksandr Usyk knocked out Daniel Dubois in the fifth round and became the undisputed world heavyweight champion for a second time on Saturday. The undefeated southpaw retained his WBA, WBC and WBO belts and regained the IBF belt he relinquished just over a year ago.

Oleksandr Usyk ppd. Lapsed fan's guide to the heavyweight division: So really, when are we getting Tyson Fury-Oleksandr Usyk? Oleksandr Usyk knocks Daniel Dubois down a second time to finally finish the fight and retain his belts.

The boxing world is set for another epic showdown when Oleksandr Usyk and Daniel Dubois meet in the much-anticipated rematch on Saturday, July 19.

Oleksandr Usyk, with his characteristic pragmatism, shut down any questions over whether he can motivate himself to keep going after a knockout win over Daniel Dubois on Saturday helped him reclaim the undisputed heavyweight boxing crown.

More than a dozen war veterans from Ukraine will be on hand when Oleksandr Usyk faces Daniel Dubois at Wembley Stadium on Saturday night in the pair’s fight to become the undisputed world heavyweight champion.

Oleksandr Usyk has now laid waste to a generation of top tier British undisputed heavyweight hopes in Tyson Fury, Anthony Joshua and Daniel Dubois.