Puerto Rico's Subriel Matias defeated Jeremias Ponce of Argentina by technical knockout to claim the vacant IBF junior welterweight crown on Saturday.
A bruising all-action battle at The Armory in Minneapolis ended soon after Matias sent Ponce to the canvas near the end of the fifth round, connecting with a brutal body shot following a flurry of punches.
Ponce looked in trouble and staggered back to his corner at the end of the round before his team stopped the fight moments later.
"We worked for 10 months really hard in the gym, I came here to win," Matias said through an interpreter after his victory.
"What I wanted to do was knock him out, and I wanted to knock him out in the sixth round. I wasn't surprised that they stopped the fight."
The 30-year-old Matias improved to 19-1 following the win. All of the Puerto Rican's 19 victories have come via knockout.
The loss was the first of Ponce's career. The 26-year-old from Buenos Aires fell to 30-1 with Saturday's defeat.
Ponce, who had launched a furious onslaught in the first round before Matias gradually got on top, said afterwards he had wanted to continue but had no complaints over his corner's decision to stop the fight.
"I'm fine. The first thing is I'm in great health and everything," Ponce said.
"But my corner knows me better than me. And it's better to take the precaution a minute earlier than a minute later. But I wanted to continue."