Vasiliy Lomachenko, widely regarded as the best pound-for-pound fighter in the world, beat British challenger Luke Campbell in a thrilling bout to win the vacant WBC lightweight title in London on Saturday.
The 31-year-old Ukrainian, who had been world champion at three different weights in only a 14-bout professional career prior to the fight, won by a unanimous decision to add the WBC belt to his WBA and WBO titles in the weight.
Lomachenko's target is to have all four major belts with Ghana's Richard Commey holding the IBF version. Lomachenko, whose record reads 14 wins and one defeat, acknowledged the toughness of the bout.
Campbell, who like Lomachenko won Olympic gold in 2012 not far from the O2 Arena where they fought on Saturday, insisted he can still win a world title.
The other world title bout on the undercard saw WBC flyweight titleholder Charlie Edwards retain his belt after replays declared it a no contest.
Edwards was knocked out by challenger Julio Cesar Martinez, but although the Mexican celebrated, he had laid one punch on the champion when he was down on a knee and it was ruled a late blow.
Alexander Povetkin -- whose last bout in the UK ended with defeat at the hands of Anthony Joshua -- took a step towards another world title tilt by beating Tyson Fury's cousin Hughie by a unanimous decision.