Unbeaten Gervonta Davis retained his WBA super-featherweight belt with a first-round knockout of former champion Hugo Ruiz in California.
It was a 12th straight win by knockout for American Davis and his 20th win inside the distance from 21 fights.
Referee Jack Reiss called a stop to the fight after two minutes and 59 seconds following a late-round bombardment which floored the Mexican veteran.
"I just wanted to put on a great performance," the 24-year-old said.
Ruiz had stepped in as a late replacement after Davis' original opponent, three-division champion Abner Mares, withdrew last month after suffering an eye injury.
Following the fight, Davis sported a T-shirt in the ring showing his support for rapper 21 Savage - the British citizen has been detained by US immigration officials who say he arrived in the country as a child and failed to leave when his visa expired.
Elsewhere, Ruiz's compatriot Rey Vargas successfully defended his WBC world super-bantamweight title against Venezuela's Franklin Manzanilla, while Alberto Machado of Puerto Rico lost his WBA secondary super-featherweight belt to American Andrew Cancio.