Five months after almost losing his right foot to infection, Matt Burton has been brought to tears as he claimed the Ironman Asia-Pacific championship in Cairns.

West Australian Burton, the 14th seed, won in a course record time of seven hours 45 minutes 20 seconds, ahead of three-time champion Braden Currie and Mike Phillips, both from New Zealand.

In the women's event, Kiwi Hannah Berry claimed her first Asia-Pacific title in eight hours 44 minutes 31 seconds, ahead of Dutchwoman Lotte Wilms and defending champion, local Kylie Simpson.

But Burton, 36, was the headline act with his extraordinary recovery from a foot abscess in January, including 10 weeks off his legs, that left him contemplating retirement.

"It unravelled on me," he said.

"I actually had a bone infection in my right small toe and I had two surgeries.

"Then we went to go back in for a third one, but they said 'well, we'll probably have to take half your foot off … so it's up to you if you want to take a big round of antibiotics and hope it works.'"Fortunately for me it did."

Burton gradually built form and fitness back in Western Australia, then headed to Cairns two weeks ahead of Sunday's race.

He was 11th after the 3.8km swim, but Burton, a gun cyclist, took the lead after the 110km mark of the 180km bike leg.

Burton was in control after the bike leg and never looked back in the marathon, winning from Currie by just over three minutes.

"To break the course record today, that's just surreal," he said.

Burton can head to October's world championships in Kailua-Kona high on confidence.

"I raced Kona two years ago and I didn't finish - I had some issues on the bike," he said.

"There's some great talent in the world, but I'm willing to go with them."

Young gun Nick Thompson, 24, learned a harsh lesson ahead of Kona after he received a five-minute drafting penalty, then crashed on a U-turn during the bike leg, ultimately finishing ninth.

In the women's race, Wilms was quickest out of the water, followed by American Lauren Brandon and Kiwi Rebecca Clarke.

The trio worked together during the bike to put some distance between themselves and the chasing pack.

But Berry made ground in a mentally challenging solo ride, then overtook both Wilms and Brandon by the 10.5km mark of the marathon.She ultimately beat Dutch triathlete Wilms by just over two minutes.

"You only dream about that kind of thing. It means a lot," Berry said.

"I definitely had to keep pushing the whole way through that last lap.

"I was on my absolute limit, to be honest, so I was just looking to get home."

Berry's focus will next turn to September's world championships in Nice.

Simpson overtook Brandon late to claim third, while former AFLW player Kate Gillespie-Jones finished ninth.