Oleksandr Usyk knocked out Daniel Dubois to reign as the undisputed heavyweight boxing champion. Round-by-round analysis.

Oleksandr Usyk knocked out Daniel Dubois in the fifth round and became the undisputed world heavyweight champion for a second time on Saturday.

"We witnessed one of the true modern-day legends tonight in action and it was a superb performance winning his IBF belt back," he said.