Top Rank's CEO Bob Arum, who co-promotes WBC heavyweight champion Tyson Fury, was all-smiles when Alexander Povetkin scored a brutal fifth round knockout over Dillian Whyte on Saturday night at Matchroom's Fight Camp in Brentwood.

Whyte, who was the mandatory challenger to Fury's world title, had dropped Povetkin twice in the fourth and appeared to be on the verge of victory - when the former WBA champion landed a vicious uppercut that knocked Whyte out cold in the fifth.

Had Whyte pulled off the win, the WBC would have mandated the winner of Fury's trilogy fight with Deontay Wilder to face him in a mandatory fight by February 2021.

Should Fury win against Wilder, the road is now clear for a full division unification with WBA, IBF, IBO, WBO heavyweight champion Anthony Joshua.

Joshua still has to overcome mandatory challenger Kubrat Pulev - in a fight targeted for December.

Arum, who also promotes Pulev, issued a warning to rival promoter Eddie Hearn, who handles Whyte and Joshua.

"Pulev will KO Joshua next. London Bridges are falling," Arum said.

Whyte, after being at the top of the WBC's rankings for years, is now at the end of the road in his long quest to force a world title fight with the WBC champion - and will have to regroup and begin again.