The 18-year-old US athlete, winner of the equivalent event in 2016 and 2017, headed a home clean sweep of the medals last year that was replicated in the qualifying as she totalled 95.25 points to lead from last year’s silver medallist Maddie Mastro, who scored 89.00.

Twenty-two-year-old Colorado local Arielle Gold, who claimed bronze at the 2018 Winter Olympic Games in Pyeongchang, finished the day in third position.

She held off two-time world champion Cai Xuetong, totalling 84.50 to the Chinese athlete’s 82.50.

In men’s qualifying, the pace was set by two Japanese snowboarders who won the first and second heats respectively - Ikko Anai, who registed 90.50, and Rabu Katayama, who scored 93.50.

Second placed qualifiers were Patrick Burgener of Switzerland, who scored 91.00, and home athlete Chase Josey, who had a best of 88.50.

Event favourite Scotty James of Australia took a third place with 86.75, as did US snowboarder Toby Miller, who scored 90.25.

Finals will be held on Saturday (December 8).