A clean routine earned her 140.49 points for a combined score of 214. Her closest competitors, from Russia, were undone by errors in their respective routines.
Kseniia Sinitsyna (RUS) scored 128.26 points to maintain her second place from the short programme and take silver, while her compatriot Anna Frolova’s fourth place was enough for her to secure the bronze overall.
As the last to take to the ice, You said she knew all eyes were on her. “I was honestly kind of nervous before my skate,” she said at the Lausanne Skating Arena.
“But I tried to keep thinking that this is just a practice, not a competition, and I think that helped me.”
The 15-year-old opened her routine with one of the most powerful weapons in her arsenal, the triple axel. She was already the first figure skater from her nation to pull off the high-scoring jump in senior competition.
“I’m happy with my triple axel, but I didn’t have a chance to put my triple toe in the second half,” You said. “Instead of a double axel-triple toe, I just did a double axel-double toe, but I think it’s a good way to be mistake-free.
“I’m a little disappointed in that, but I’ll practise more and avoid that in future,” You said.
You had arrived in Lausanne just days after competing in the Rep. Korean national championships, where she won her fourth national title.
“I think I did pretty good here even without getting to rest. I’m happy with the result today and I’m very thankful that my fans keep watching me and cheering me on,” she said.