Yuto Totsuka led a Japanese men's podium sweep, while Mitsuki Ono and Sena Tomita finished 1-2 in the women's competition Saturday in the snowboarding halfpipe World Cup round at California's Mammoth Mountain resort.
Totsuka scored 94.75 to win his first World Cup gold in three seasons, ahead of countrymen Ruka Hirano (91.75) and Kaishu Hirano (89.25). Shuichiro Shigeno placed sixth as Japan claimed four of the top 10 spots.
"I haven't had a set routine lately, so I'm really happy," the 22-year-old Totsuka said.
"Today was different from usual in that I felt like I could make my tricks from before the start. I felt good for the first time in a long time, and it's given me confidence."
Ono (95.50) won her second straight World Cup competition after opening her account for the season last month in Laax, Switzerland. Beijing Winter Olympic bronze medalist Sena (88.50) finished ahead of third-place Maddie Mastro of the United States.
"The conditions were difficult but I was able to stay calm and adjust quickly," the 19-year-old Ono said. "It's given me confidence and I feel like I've improved as well."
Japan's Ruki Tomita, who won bronze in Laax, was seventh.