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 retained his WBA, WBC and WBO belts and regained the IBF belt he relinquished just over a year ago.

Oleksandr Usyk once again became the undisputed heavyweight champion of the world with a fifth-round knockout win over Daniel Dubois at Wembley Stadium in London, England.