Filipino soldiers and refugees caught up in weeks of fighting with Islamist militants were given some rare respite on Sunday when they were treated to a live screening of Manny Pacquiao's World Boxing Organisation welterweight world title defence.

However, the excitement and noisy fanfare at a government centre soon turned into shock and disappointment when the local boxing hero suffered a stunning points loss to unheralded Australian challenger Jeff Horn in Brisbane.

The 29-year-old former school teacher extended his unbeaten record to 17-0-1 in front of a 50,000-strong hometown crowd, but some Filipinos found it difficult to accept the unanimous decision after they felt Pacquiao had dominated the fight.

Pacquiao's long-time trainer Freddie Roach predicted the fight would be short and sweet but Horn — unbeaten in his 17 previous professional fights — applied pressure by winning some of the early rounds and Pacquiao needed treatment during the 6th and 7th rounds for a cut on the top of his head that resulted from a clash of heads.

The judges scored the fight 117-111, 115-113 and 115-113.

Roach said the quietly spoken Horn was "a little bit rougher than I thought he was. Maybe a little bit more physical."

"Like every time you come you come out of a clinch in a headlock, something is wrong there," he said. "I don't know if the referee couldn't control that or what it was.

"But, I thought it was a pretty close fight. I thought Manny had a real good round in the 9th - I thought it was maybe a two-point round - and I just told Manny, 'give me one more of those and the fight's over,' but he just couldn't do it. We lost the decision."

Roach said he couldn't judge the fight, given how close he was.

"I hear there's a lot of people think it's controversial, think Manny won, but it went the other way and we have to live with that."