Kim and Hirano reign supreme on Copper Mountain

Kim scored 93.75 in Copper Mountain, Colorado, to claim her second 1000-point haul of the season.

Compatriots Maddie Maestro and Kelly Clark came second and third, with respective scores of 90.75 and 83.75.

For 17-year-old Kim, it proved to be a happy hunting ground once again after she triumphed on the home slopes last year.

"Winning the first national Olympic qualifier event feels awesome," said Kim.

"But the halfpipe makes it kind of feel home and all the nerves go away. Dropping in I'm just excited to trying new stuff."

In the men's competition, it was Japan's Ayumu Hirano who prevented another home victory in front of the American crowds as he took the title ahead of home heroes Ben Ferguson and Shaun White.

Despite being just 19, Hirano is a Winter X Games gold medallist in the SuperPipe and claimed halfpipe silver at the Winter Olympic Games in Sochi in 2014.

And he blew away the competition to score 95.25, which he did on his second run, with Ferguson his nearest challenger on 89.75. White's third run of 89.25 was his best and enough for third on the day.

Hirano's win leaves him top of the overall standings after two World Cup rounds, following his second-place finish in Cardrona, New Zealand, in September. Compatriot Yuto Totsuka is second, with Ferguson third.