A star was born on Tuesday morning in the Taebaek mountains as the American teenager Chloe Kim launched out of a halfpipe into the hearts of the world, delivering on her long-held promise with an Olympic gold medal.

The precocious 17-year-old from greater Los Angeles earned a score of 93.75 in her opening run at the Phoenix Snow Park. That was more than enough to clinch the title, but Kim managed to top it with a near-perfect mark of 98.75 on her third and final attempt with back-to-back 1080s, punctuating her arrival with the daring maneuver she remains the only female rider to have landed in competition.

Liu Jiayu won the silver with an 89.75 to become the first Chinese snowboarder to win an Olympic medal while Arielle Gold of the United States took the bronze with a mark of 85.75 on a clutch final run, but they were reduced to bystanders on a day that quickly took the shape of a coronation for the young Korean-American competing in the country where her parents were born and raised before emigrating to the United States.

“I don’t really know what’s happening right now,” Kim said at the bottom of the hill in the immediate aftermath. “This is the best outcome I could ever ask. It’s been such a long journey and just going home with the gold is amazing.”

She added: “It means a lot just being able to do it where my family is from. A lot of pressure, but I’m happy I was able to do it here and do it for the fans and the family. It was a really fun moment for everyone.”

The oppressive conditions that had made a mockery of the women’s slopestyle one day earlier were a distant memory as Tuesday’s halfpipe final went off beneath a cloudless sky and only the occasional light breeze. Kim was the last of the 12 finalists to take off down the hill after posting a 91.50 in qualifying runs, nearly four points better than any of her rivals.

The American put down a solid first run highlighted by an inverted 540 and a single 1080, which she landed with almost casual indifference, prompting oohs and aahs from the throngs of fans in the gallery every time she left the pipe. It was clear at the finish she’d set the bar high, but Kim threw her hands over her face and the crowd roared when the score of 93.75 flashed on the monitor. Worryingly for her rivals, there was still room for improvement.

That it already felt like a race for silver, with none of the 11 finalists within eight points of the leader, did little to dissipate the electric atmosphere as the riders underwent their second runs.

Kelly Clark, the gold medalist at Salt Lake City 2002 and one of the Americans who went to Sochi instead of Kim, moved into a medal position with a crisp set, while Jiayu’s huge amplitude and solid grabs earned a 89.75 to pull to within four points of the pace, at worst a reliable silver medal run. Kim then followed with a double 1080 attempt, but couldn’t stick the landing on the back end.

The third runs opened with a pair of strong American efforts with Gold (85.75) pushing US team-mate Clark (83.50) off the podium. One by one the riders failed to even approach Kim’s score. That left it up to Jiayu, who went for broke with an early 900 and continued to pick up points along the way, but her fall on an audacious 1080 at the finish meant the gold was Kim’s before the scores were even calculated.

“You have to feel like that, that you are the best, you can beat everybody,” Jiayu said through a translator. “If you don’t have that feeling you can’t be a top athlete.

“But she is amazing.”

Already an Olympic gold medalist as she stood atop the hill for her final run with only a victory lap between her and the silverware, Kim made one last attempt at the double 1080s and stuck it with flair to launch the crowd into hysterics amid chants of ‘U-S-A!”.

“I just knew that I wasn’t going to be completely satisfied taking home the gold but knowing I could have done better, just done a better run and ride the best I could,” Kim said. “I just wanted to show myself that I could do it and I could put down the best run I could do.”

With Tuesday’s win, Kim became the youngest ever female athlete to capture Winter Games gold on snow, surpassing Switzerland’s Michaela Figini, who was 19 days older when she won the ladies’ downhill in 1984. And at 17, there’s every reason to expect the best is yet to come.

“When you work for something for so long and it’s finally here and you go home with the best possible outcome, it’s amazing,” she said. “Just realizing how far I’ve come as a person, as an athlete, standing on that podium. Everything just combines and you just realise you’ve won and you did a good run, and you’re really excited about everything.”