But he left himself open to a number of challengers, mentioning three names in in his post-fight interview: Tyson Fury, Anthony Joshua, Joseph Parker.

Oleksandr Usyk knocks out Daniel Dubois in Round 5 to become the undisputed world heavyweight champion again 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.