South Korea's Lee Hae-in competes in the women's free skating during the ISU World Figure Skating Championships 2023 in Saitama on March 24, 2023. (AFP, Yonhap)

Behind career-best performances by its two biggest stars, South Korea ranked second after the first day of the International Skating Union (ISU) World Team Trophy in Figure Skating on Thursday.

Lee Hae-in, the reigning world silver medalist in the women's singles, won the short program with a personal-best 76.90 points at Tokyo Metropolitan Gymnasium in Tokyo.

By finishing first in her discipline, Lee scored 12 ranking points for South Korea. Her previous personal-best score of 73.62 points had been set at the world championships last month.

In the men's singles Thursday, Cha Jun-hwan, who'd also won silver at the world championships last month, set a new personal-best with 101.33 points to finish second in the short program. Cha, whose previous career high was 99.64 points from the world championships, is the first South Korean figure skater to top the century mark in the short program at an ISU event. He collected 11 ranking points for the country.

Also on Thursday, Kim Ye-lim ranked seventh in the women's short program for six ranking points, while Lee Si-hyeong picked up three ranking points by finishing 10th in the men's short program.

In the ice dance, Hannah Lim and Quan Ye scored seven ranking points by finishing sixth in the rhythm dance.

With 39 points overall, South Korea is in second place, 11 back of the United States.

The World Team Trophy continues Friday with the short program for the pairs, free dance for the ice dancers and the free skate for the women's singles skaters.

The competition will wrap up Saturday with the pairs free skate and the men's single free skate.

South Korea is competing at the World Team Trophy for the first time, and Lee Hae-in and Cha Jun-hwan helped the country qualify with their silver medals at the world championships.

Lee became the first South Korean figure skater since Kim Yu-na in 2013 to win a world championships medal, while Cha became the first South Korean male figure skater to stand on the podium at a world championships. (Yonhap)