US teenager Jamie Anderson outscored her closest female rival by 24 points at the end of three runs down the 800m slopestyle course, while Norway's Mikkel Bang was also impressive, finishing 12 points ahead of the second place-getter in the men's division.
Anderson won her first New Zealand slopestyle competition on her third visit down under.
The 18-year-old claimed the winner's cheque for $5000 and hopes to repeat the dose in today's half-pipe event.
Anderson is a back-to-back winner of half-pipe gold medals at the Winter X Games and said her win was "really cool" given the tough conditions.
Bang lived up to his name and brushed aside the challenging conditions to win yesterday afternoon, after finishing third in the same event last year.
"I was up here really early this morning and things looked bad then, but I just continued to ride better and better," he said.
Bang's winning final run included a switch frontslide boardslide, cab 540 nose tap, cab 720 mute, switch backside 900 mute, 270 on the rail, finishing with an alley-oop wallride to end with a flourish.
Anderson impressed with her final run and judge Jason Grossi praised her outstanding riding ability.
"She dominated from the very beginning and was riding stronger than some of the men," he said..
The best of the New Zealand riders was Wanaka's Shelly Gottlieb, who came fourth in the women's section.
A recent Queenstown recruit, Australian Callie Conaghan, was fifth.
It was a tough day for New Zealand's male snowboarders, with Queenstown's Nick Hyne the best of them, finishing eighth.
However, Mitchell Brown (12th) and Aucklander James Hamilton (11th) picked up enough points from their respective placings to move into the world top 10.
Bang was joined on the slopestyle podium by Canadian Charles Reid (second) and US rider Charles Guldemond.
Anderson stepped up ahead of the Netherlands' Cheryl Maas (second), while Spencer O'Brien, of Canada, was third.
The event finishes today with the premier event - the half-pipe finals - starting at Snow Park from midday.
