In doing so, they became the first Japanese skaters to earn the pairs crown at the World Championships.

They built an overnight lead of more than six points over last year's champions Alexa Knierim and Brandon Frazier of the United States after a strong short programme at the Saitama Super Arena.

Knierim and Frazier applied the pressure with a season's best 142.84 points in the free skating to finish with 217.48.

However, Grand Prix Final and Four Continents winners Miura and Kihara held their nerve to improve on their silver at last year's World Championships.

Performing to Atlas: Two by Sleeping At Last and Shared Tenderness by Karl Hugo, they notched a personal best 141.44 points to finish on 22.16.

Miura took a fall on their final throw triple loop, but was relieved with the gold medal.

"After the Four Continents, we worked really hard to have no regrets, and in the short programme we were able to show what we’ve been working on, but today in the free skate my weakness came out and I feel regret, but I am happy," she said.

Kihara expressed his pride at success at his home World Championships.

"I am really happy to win here in my home country," he said.

"The first half of the season was a bit difficult for us, because Riku got injured, however, because of that we were able to acknowledge how strong our bond is.

"Our trust for each other grew, but during this season our weakness came out a few times in our free skate, so for next season we hope to come back stronger."

European champions Sara Conti and Niccolò Macii of Italy notched a personal best 134.84 in the free skating, and took bronze with 208.08 on their World Championships debut.

The men's event began today with the short programme, and Japan's reigning champion Shoma Uno leads on 104.63 points.

Uno won men's singles silver at the Pyeongchang 2018 Winter Olympics and bronze at Beijing 2022, and skated clean after an injury scare to his right ankle in the build-up to the World Championships.

Last year's world junior champion Ilia Malinin of the US is in contention with 100.38 in second place, followed by the 2022 Four Continents champion Cha Jun-hwan of South Korea in third on 99.64.

France's European champion Adam Siao Him Fa had to settle for 12th with 79.78, and it was a difficult day for Japan's Grand Prix Final silver medallist Sōta Yamamoto of Japan, who is 17th on 75.48.

The World Championships is set to continue with the women's free skating and the start of the ice dance.

Reigning world champion Kaori Sakamoto of Japan holds a lead of 5.62 over South Korea's Lee Hae-in after the short programme.