Figure skating star Kim Yu-na performed a flawless short program to take an overwhelming lead at the South Korean national championships on Saturday, her last prep for the Sochi Winter Olympics.

At Goyang Oulimnuri Ice Rink at Gyeonggi Province, northwest of Seoul, Kim scored 80.60 points to open a 22.12-point lead over Kim Hae-jin after the ladies' short program.

The free skating is scheduled to begin at 12:54 p.m. on Sunday.

Kim, the reigning Olympic gold medalist and two-time world champion, won the national title last year.

This is Kim's final competitive appearance at home and also her last event before the Sochi Winter Olympics next month in Russia. The 23-year-old has already said she will retire after Sochi, where she will aim to become only the third woman to successfully defend an Olympic figure skating gold.

Performing to a musical score titled "Send in the Clowns," Kim opened her short program with a flawless triple lutz-triple toe loop combination. She followed up with a picture-perfect triple flip. Elegant spins and steps set up Kim for a smooth double axel midway through the program.

Kim finished off her program with a series of textbook spins and step sequences, delighting the sellout crowd of 3,500.

Though the score represents the highest mark of Kim's decorated career, it won't be recognized by the International Skating Union (ISU) because it came at a domestic event. Kim owns the official world record in the short program under the current judging system with 78.50 points, set in her Olympic gold medal-winning performance in Vancouver in 2010.

Kim looked shaky in warmups earlier on Saturday and said afterward that she was pleased to have skated a clean program in competition.

"I was able to stay calm, and I am grateful for such a high score," Kim said in a televised interview. "But the most important thing is to do well at international events. If I can skate at the Olympics as cleanly as I did today, I should be able to post a good result."

Kim won her first competition of the season last month in Croatia, taking the minor event called the Golden Spin of Zagreb with ease, but she also made uncharacteristic mistakes on what had been routine jumps to her.

Kim's standing in the competition after the opening day had essentially been a foregone conclusion. She said after the short program that her focus this weekend would be to fine-tune her programs and try to make necessary improvements before Sochi.

In Croatia, Kim had scored 73.37 points in the short program, the fifth-highest mark of her career.

Kim Hae-jin, a 17-year-old set to make her Olympic debut next month, finished a distant second at 58.48 points. Fellow Olympic debutante, Park So-youn, ended in a disappointing fifth with 52.31 points after a mistake-laden program.  (Yonhap News)