Spain's Castellet topped the podium in the ladies' halfpipe, a result that leaves her second in the standings with one event – in Mammoth Mountain, in the United States, in March – left to go.
Castellet, 29, racked up an overall score of 90.25, finishing clear of halfpipe leader Cai Xuetong (88.25) of China while Japan's Sena Tomita was third with 87.75.
The Calgary champion, a silver-medallist at the 2015 World Championships, is 120 points clear of third-placed Chloe Kim on the halfpipe leaderboard but table-topper Xuetong currently enjoys a 780-point advantage.
Kleveland and Iwabuchi enjoy slopestyle success in Silvaplana
Kim and Totsuka take halfpipe glory in Aspen as White makes comeback
Kim and Totsuka take halfpipe glory in Aspen as Shaun White makes competitive comeback