Queenslander Liam Paro has produced one of the great performances in Australian boxing history, beating the Puerto Rican "bogeyman" Subriel Matias to win the IBF junior welterweight title and set up a big fight back home.

The 28-year-old Australian southpaw was a massive underdog, but won 115-112 on two cards and 116-111 on the third in Manati, Puerto Rico.

The win for Paro (25-0, 15 KOs) ranks alongside some of the great world title victories overseas by fellow Australians Lionel Rose, Jimmy Carruthers, Johnny Famechon, Kostya Tszyu, Daniel Geale and George Kambosos.

"I'm a true warrior, I've got the heart of a lion, I showed that," Paro said on broadcaster DAZN.

His persistent jab, uppercuts and combination punches carried the day against Matias, who was rarely able to show his renowned pressure and found it hard to counter the clever movement of the challenger.

Paro had a point taken off in the seventh round by referee Luis Pabon for hitting to the back of the head.

It was a contentious ruling, described by the fight commentators as "disgraceful," "disgusting" and "ridiculous".

Happily for the Australian it didn't affect the outcome, as he continued to flummox the champion (20-2, 20 KOs).

Paro banked rounds early against the notoriously slow-starting Matias.

While the Puerto Rican landed some powerful flurries, especially in the middle rounds, Paro wasn't discouraged by the point deduction and clearly won the last few rounds.

"I know the hard work I've put in, I'm always the hardest worker in the room," Paro said after going 12 rounds for the first time.

"I keep proving everyone wrong and just took the biggest test and came out on top."

The win also enabled Paro to deliver on his world title promise to his friend Regan Grieve, a promising rugby leaguer player who died by suicide in 2015.

"I made a promise to my friend (who) passed away (and) I'm a f*****g man of my word," Paro said.