Australia's Scotty James his fourth world snowboard half-pipe title at St Moritz

Scotty James has demonstrated once again why he is one of the greatest Australian winter sports athletes in history as he landed his fourth world snowboard half-pipe title with another brilliant daredevil display amid the snowfall in St Moritz.

The 30-year-old Melburnian grabbed the long-awaited first Aussie gold of the FIS snowboard, freestyle and free ski showpiece on Saturday's penultimate day.

His magnificent win came soon after the duo of Cam Bolton and Mia Clift took an unexpected silver in the snowboard cross mixed team final, boosting Australia's tally to three medals following the bronze won in the dual moguls by Matt Graham in the first week.

"Half-pipe is a scary sport and it gets even scarier when conditions are tough," James said. 

"I am really pumped and I felt that I had to be resilient today, so I am stoked. To have won four world titles, I'm pinching myself."

The snow was tumbling heavily at the Swiss resort as James, who in January had matched the legendary US rider Shaun White with a fourth straight X-Games half-pipe gold, set out on his latest historic quest, seeking to add to his three successive world titles in 2015, 2017 and 2019.

On both runs, he led the way, firstly with an 89.50-point routine before a supreme final run that earned him 95.00.

His complex but superbly executed winning outing began with a switch McTwist Japan and ended with a switch backside double cork 1260 Weddle, before the even more risky post-competition Aussie tradition of a celebratory "shoey" as he supped champagne from his snowboot.

He saw off the challenge of Japan's former world champ Totsuka Yuto, who had set the pace in qualifying with a fantastic 97.00 routine but had to settle for silver with a 92.50-point run, while Yuto's compatriot Hirano Ruka grabbed bronze (92.00).

"Coming out this week was such a challenge. I was definitely not sitting there feeling OK when Ruka and Yuto were dropping in. They've been riding incredibly well all season and I've had some great battles with them," James said.

His fifth world championship medal equalled the Australian-record tally of freestyle skier Graham, his fellow 30-year-old, but none of the moguls exponent's gongs had been of the golden variety.

The victory only sets James up for the prize he really needs to confirm himself as Australia's winter sports greatest — the Olympic gold in Italy next year to go with his bronze in Pyeongchang in 2018 and silver in Beijing in 2022.

The silver for the all-Victorian pairing of 34-year-old Bolton and 20-year-old Clift was a welcome bonus for the team after the other, more fancied Australian pairing of Adam Lambert and Josie Baff just failed to make the four-racer 'Big Final' and ended up finishing sixth overall.

In the inaugural mixed team final, only the French duo of Loan Bozzolo and Julia Pereira de Sousa could defeat the Aussie pairing, with Clift producing a brilliant leg to get second-place ahead of Switzerland's Valerio Jud and Sina Siegenthaler.

In the women's snowboard half-pipe, American star Chloe Kim scored 93.50 in her first run for her third world title after wins in 2019 and 2021, while 15-year-old Sara Shimizu, from Japan, claimed silver with 90.75.

AAP