Olympic champion Yuzuru Hanyu had to settle for third place after the men's short program Friday at the Four Continents Championships.
Hanyu, aiming for his first title at this competition, looked slightly rusty and scored 97.04 points to finish behind U.S. national champion Nathan Chen (103.12) and Shoma Uno (100.28).
Skating to Prince's "Let's Go Crazy" Hanyu, who missed the national championships in December because of the flu and had not competed since, nailed his opening quad but his second one turned into a double salchow-triple toe loop combination jump at Gangneung Ice Arena.
"There is still work for me to do and I am left with a few regrets but I think I was able to do what I could. I just have to try and improve the things I am doing," Hanyu said.
He said his mistake on his quad salchow came about as a result of overthinking.
Uno, the national champion, opened with a slightly shaky quad flip but then landed a quad toe loop-triple toe loop combo. His excellent performance also included a triple axel and earned him at least 100 points for the first time.
"I prepared well both mentally and physically," Uno said. "I am happy that finally for the first time this season I have pulled all my jumps together.
"I am relieved. I can perform even better and get an even better score."
China's Jin Boyang was fourth with 91.33 points and Canadian three-time world champion Patrick Chan placed fifth with 88.46. Keiji Tanaka was 11th.
Japan's Kana Muramoto and Chris Reed took ninth in the ice dance won by Canada's Tessa Virtue and Scott Moir. Emi Hirai and Marien de la Asuncion were 12th.