Liu led after her short program to “Gypsy Dance II” from Don Quixote, then won the free skate with a program that included seven triple jumps and three Level 4 spins. The 16-year-old from Clovis, California, scored 207.40 points in total to earn gold in her second consecutive Challenger Series event.
Ekaterina Kurakova of Poland was second and Viktoriia Safonova of Belarus was third.
Earlier this year, the U.S. clinched two men's and two women's spots for Beijing based on their results from the world championships. Vincent Zhou's victory at the Nebelhorn Trophy on Friday night gave them a third men's spot, too.
The U.S. will send three ice dance entries and two pairs teams to the Winter Games in February.