SAN JOSE, Costa Rica — Trey Lippe Morrison was in uncharted waters Wednesday night.

Not only was he boxing outside the United States, but also the son of former heavyweight champ Tommy “The Duke” Morrison was taken further than in any of his previous 15 fights.

A crushing right to the body spelled the end for Pedro Martinez.

After the final blow to the ribs, Martinez dropped his gloves and the referee stepped in to stop the fight at the 50-second mark of the sixth round at the Gimnasio Nacional Eddy Cortés.

Martinez had looked uncomfortable in the previous two rounds, constantly squinting his eyes.

Morrison, in action for the first time in 13 months, mostly due to injuries, had been scoring in the final couple of rounds with body shots.

“I just tried to stay calm and relaxed, do our thing, work the angles,” Morrison said following the fight. “I could see when I was working the angles in the sixth round he was getting him. He was getting a little tired and couldn’t keep up.”

The longest Morrison had gone was four rounds during a TKO against Thomas Hawkins on Jan. 23, 2016 at Buffalo Run Casino.

His previous longest had been in his previous two fights, each going three rounds.

Two were in the second and the rest were first-round stoppages.

Morrison wasn’t worried that he was extended.

“There was no rush, just let it come,” he said. “As for the next step, me and my team are going to get together.”

Prior to Wednesday’s internationally televised bout, Morrison had fought just twice since 2016.

Eleven of his first 13 outings were in Miami, but the previous two had been at Deadwood, South Dakota, and Oklahoma City.

Martinez suffered just his second loss in 12 pro bouts.

The card was part of a DiBella Entertainment Broadway Boxing event.