Eddie Hearn, promoter of once-beaten flyweight contender Jay Harris, believes the boxer proved his worth as a future world champion last Saturday night in Frisco, Texas.

Harris, 29-years-old, lost a twelve round unanimous decision to dangerous puncher - WBC world flyweight champion Julio Cesar Martinez.

Harris made things very tough for Martinez, who dropped the young boxer and had to dig deep in certain rounds to deal with Welsh fighter's accurate boxing style.

Harris was not expected by many to last more than a few rounds.

The contest took place on the undercard to the welterweight fight between Mikey Garcia and Jessie Vargas.

"I really believe he can be a world champion," said Hearn to BBC Sport. "I'd love to do something with Jay in the future."

The judges saw it 118-109, 116-111 and 115-112 for Martinez.

"[Harris] was absolutely brilliant. Martinez is an absolute beast and he was hitting Jay with shots. He marked up his face and I thought it was going to be all over in three rounds. But Jay boxed absolutely sensationally and around halfway I actually had it near enough all-square. I thought one of the score cards (118-109) was disgusting and I thought the one that was 115-112 was about right," Hearn said.

"But I'll tell you what, Jay boxed the best flyweight in the world, someone who is going to be a pound-for-pound great, one of the most fearsome punchers in the game and Jay took all his shots and he should be very proud of himself.

"He's going to come back and he's going to have a big future. He's done more in defeat than in all his wins combined, because he's never boxed at that level before. My worry was that he wasn't a world-class fighter, but he proved he absolutely is a world-class fighter."