Teofimo Lopez beat Vasyl Lomachenko by a unanimous points decision in Las Vegas to become the undisputed world lightweight champion.
The American’s win over the Ukrainian means he now adds the WBA, WBO and WBC ‘Franchise’ titles to his IBF belt.
Lopez, 23, dominated the first half of the fight and, despite a late rally by Lomachenko, was awarded a 116-112, 119-109, 117-111 win by the judges.
“I am ready to take over the world,” Lopez said.
The result means he is the youngest fighter to become a four-belt undisputed champion and he maintains his unbeaten record with 16 wins from 16 bouts.
The fight between the two rivals had been eagerly awaited but took place without any fans because of the coronavirus pandemic.
Lomachenko, 32, was kept quiet early on and, although he put in a strong effort in the later rounds, it was not enough to stop him suffering a second defeat from his 15 fights.
“I think I won the fight,” Lomachenko said after his first loss in six years. “But I am not going to argue it now.
“In the first half of the fight he won more rounds. In the second half I took it over. I don’t agree with the scorecards.”