Estonia's 16-year-old Kelly Sildaru got the better of Canadian Olympic champion Cassie Sharpe to win the opening International Ski Federation Women's Freestyle Skiing Halfpipe World Cup of the season in Copper Mountain.
Sharpe, who clinched gold at Pyeongchang 2018 in February, was the top qualifier for today's final on American snow.
But she had to settle for silver at the Colorado resort as Sildaru, who qualified in second, shone with an excellent score of 93.00 points.
The teenager put down three superb runs which all scored 89.00 points or higher en-route to a maiden World Cup victory.
Her second outing was nearly perfect, featuring back-to-back 900s and a switch left-side 900 safety.
"I didn't really expect to win today at all," said Sildaru.
"These girls are skiing so well and have inspired me so much, and I haven't been skiing halfpipe so much - the last time was two-and-a-half months ago in New Zealand - so I'm pretty stoked about the result today."
Sharpe took silver with 90.50 points as American Brita Sigourney, the Olympic bronze medallist, managed 88.00 for a medal of the same colour on home snow.
There was a home victory in the men's event as Colorado-native Aaron Blunck made the most of familiar conditions.
He pulled off a switch left double cork 900 Japan trick, a switch right double 1080 safety, a left double flare 1080 safety and a right double 1440 tail as he scored 96.25 points.
"I've been working on that run for a little bit now, so to land it in the first contest of the year has got me so hyped," said Blunk.
"I just about put it down in the first run but I had a little hand drag, but that helped me get the nerves out.
"In that second run I was just thinking, 'you got this, let's go put it down' and I did and I'm stoked."