American Shakur Stevenson defeated Edwin De Los Santos to claim the WBC lightweight title in Las Vegas and become a three-division world champion.
The 26-year-old won the vacant title by a unanimous decision, with two judges scoring it 116-112 and one 115-113.
Stevenson, who has previously been featherweight and super-featherweight champion, remains unbeaten since his professional debut in 2017.
“I had a bad performance tonight,” said Stevenson, who is now 21-0.
The 2016 Olympic silver medallist added: “I wasn’t feeling too good. I don’t make no excuses, I came here, got the victory, that’s all I wanted to do.
“I got to go back to the drawing board and work on a lot of things and come back.”
Dominican De Los Santos, who landed just 40 punches in the 12 rounds, criticised Stevenson’s performance.
“I came to fight, he came for a track meet,” he said. “Stevenson decided not to fight. He was gifted the title but I am the champion of the people.”