Australian Liam Paro has lost his IBF super lightweight belt after suffering a split-decision defeat to New Yorker Richardson Hitchins in Puerto Rico on Saturday night (Sunday AEDT).

Paro made a bright start to the bout in San Juan, with the Mackay talent on top for three of the first four rounds.

But Hitchins turned the 12-round contest on its head after that, with two of the three judges scoring the American the winner 116-112.

The other judge - Nelson Vazquez - scored the bout 117-111 to Paro in a scorecard that was widely panned on social media.

A win for Paro would have set up a blockbuster fight in Australia, possibly against compatriot and former lightweight world champion George Kambosos Jr.

Paro's record now stands at 25-1, and it remains to be seen what his next move will be.

Hitchins improved to 19-0, and he was overcome by emotion after being announced the winner.

The 27-year-old called out fellow American Teofimo Lopez straight after the bout.

"I want Teofimo in New York, Brooklyn. Unification," Hitchins said.

"I think that would be one of the biggest fights of 2025, a very lucrative fight.

"I don't belong in the ring with nobody else but the top level of boxing."

Paro labelled Hitchins a "quitter" in the lead-up to Saturday's bout, and promised to take his opponent to some "very dark places".

The Australian had the better of the early exchanges, but Hitchins' left-right combo came to the fore from round five onwards and he was deservedly crowned the winner.