There are three runs in the final round, and each competitor's best score determines the final standings. Kim had 93.75 points from her first run and 41.50 points from her second run.
With her victory, Kim is now the first woman to win a medal at both the Olympic Winter Games and Winter Youth Olympic Games in snowboard. The 17-year-old also became the youngest American woman to win an Olympic gold medal in a snowboard event.
Making her Winter Games debut, Kim was dominant from the qualifying round on Monday. She was the only one among 24 contestants to score more than 90 points in both qualifying runs. In the finals, she was also the only rider among 12 competitors to top the 90-point mark.
"When I landed and realized that I've won the first (gold medal), words that came into my mind were mom, dad and family," she said.
"I don't know how I'm going to celebrate tonight. When I go home back to the US, probably my mom would throw a little party for family and friends."
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