Chloe Kim wins first event of Olympic season as Maddie Mastro crashes out

• Olympic champion lands pair of 1080s at Copper Mountain
• American medal contender Mastro crashes hard on first run
• Kim, 21, is unbeaten in five events since return from hiatus

Chloe Kim won her first event of the Olympic season at the Dew Tour on Sunday while Japan's snowboarders showed why they are tipped for the podium at next year's Beijing Winter Olympics with Yuto Totsuka winning the men's halfpipe and Ayumu Hirano becoming the first to land a frontside triple cork 1440 in competition.

Kim, the reigning Olympic women's halfpipe champion, came out on top with a score of 96.00, beating out Spain's Queralt Castellet and China's Xuetong Cai.