Two-time U.S. champion Alysa Liu was the shock leader after stumbles by a trio of favorites in Wednesday's women's short program at the World Figure Skating Championships in Boston.

The 19-year-old American led 24 qualifiers for Friday's women's free dance final by winning the short program with 74.58 points, followed by Japan's Mone Chiba on 73.44 and U.S. teen Isabeau Levito on 73.33.

"Doesn't really change anything," Liu said. "My goals are still the same. I want to put out a really good performance for my free skate.