Japan's Kaori Sakamoto made a strong start to her women's singles title defense Wednesday at the ISU World Figure Skating Championships, leading the field with the highest-scoring short program of the season.

The 22-year-old Beijing Winter Olympic bronze medalist scored 79.24 on the opening day of the championships at Saitama Super Arena near Tokyo and leads South Korea's Lee Hae In by 5.62 heading into Friday's free skate. Japan's Grand Prix Final winner, Mai Mihara, finished third with 73.46.

Aiming to become the first Japanese woman to go back-to-back as world champion, Sakamoto received an ovation from the home crowd after executing all of her elements, including a double axel, triple lutz and triple flip-triple toe loop combination.

Japan's Kaori Sakamoto performs her women's singles short program at the ISU World Figure Skating Championships at Saitama Super Arena in Saitama, eastern Japan, on March 22, 2023. (Kyodo)

"I could skate without any worry," Sakamoto said. "I think there wasn't much sense of speed, but I'm satisfied to put in my best performance of the season. I hope to come up with a perfect free skate and end with a smile."

Riku Miura and Ryuichi Kihara earlier took a step toward Japan's maiden pairs world title, topping the short program ahead of American rivals Alexa Knierim and Brandon Frazier.

Japan's Mai Mihara performs her women's singles short program at the ISU World Figure Skating Championships at Saitama Super Arena in Saitama, eastern Japan, on March 22, 2023. (Kyodo)

Runners-up to the American duo at last year's worlds, Miura and Kihara earned a personal-best 80.72 points, the highest score for the segment by any pair this season.

They will take a 6.08-point lead over the reigning world champions into Thursday's free skate, with Italy's Sara Conti and Niccolo Macii a further 1.4 points back in third.

Japan's Riku Miura (L) and Ryuichi Kihara perform in the pairs short program at the World Figure Skating Championships at Saitama Super Arena in the eastern Japan city of Saitama on March 22, 2023. (Kyodo) ==Kyodo

Saitama is hosting the competition for the first time since 2019, with Japan's Shoma Uno also vying to defend his men's singles crown.

Uno received treatment on his right ankle after falling during practice on Wednesday but is expected to be "fine" for the following day's short program, a Japan Skating Federation official said.

Skaters from Russia, a powerhouse of women's figure skating, remain banned from the world championships over the country's invasion of Ukraine.

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