Japan's Shoma Uno said he felt "relief" after shrugging off mental doubts and injury to retain his world figure skating title in front of an adoring home crowd on Saturday.

Uno held off a challenge from American teenager Ilia Malinin -- who became the first skater ever to land a quadruple axel at a world championships -- to claim gold in Saitama, north of Tokyo.

Uno went into the competition anxious about his jumps after twisting an ankle in practice one week earlier, then injuring it again on the eve of the short programme.

But he stamped his class all over the event to earn an overall score of 301.14 and finish ahead of South Korea's Cha Jun-hwan on 296.03 and third-place Malinin on 288.44.

Olympic champion Nathan Chen is currently taking a break from competition, while Russian skaters were banned over the war in Ukraine.

Uno said he "needed to give more in the competition than in practice" to win the title, and breathed a sigh of relief when it was over.

"If I had to do it again, it would be impossible," said the 25-year-old.

"If you ask what I am capable of doing right now, I can't do any more than that."

Uno's victory gave Japan its third gold medal of the competition, after Kaori Sakamoto retained her women's title the previous night and Riku Miura and Ryuichi Kihara won the pairs event.

Uno stumbled on an early jump but delivered the rest of his programme with smooth precision, before collapsing on the ice at the finish.

"These past two weeks have been very tough because I've been in bad shape and I've caused problems for the people around me," he said.

"But I was able to pay them back and show my gratitude with my performance today."

Malinin lands quad axel

Uno had to be at his best to beat the 18-year-old Malinin, who lived up to his own hype with another electrifying performance.

Malinin became the first skater ever to land the ultra-difficult quadruple axel in competition in September last year, in only his first season in the senior ranks.

He has dubbed himself "QuadGod", and he delivered on his promise on the world stage by nailing the move again with the first jump of his routine.

The rest of his performance was not enough to earn him silver ahead of Cha, but he said it was "a huge achievement" to reach the podium.

"I was just very happy that I did my job, that I came here and was able to stay on my feet," Malinin told reporters, wearing a cap wearing a Japanese translation of his "QuadGod" nickname.

"Next year, I think it will be a lot more beneficial if I practice the artistic side too."

Earlier in the day, American ice dancers Madison Chock and Evan Bates hailed their own "grit" as they finally claimed their first world title, after recovering from a fall in the free dance.

Chock and Bates took gold in the 10th world championships of their career, beating Italy's Charlene Guignard and Marco Fabbri and Canada's Piper Gilles and Paul Poirier.

Chock said the experience the pair had picked up over their long careers helped them shrug off her tumble midway through their routine.

"I know that we wouldn't be sitting here today without many of those challenges that we've faced, not just this season but throughout all the many seasons of our career," she said.

"We have really persevered and shown a lot of grit. I think maybe our performance today was a little reflection of that."

Chock and Bates, who last year got engaged to be married, finished with 226.01 points overall, ahead of Guignard and Fabbri's 219.85, and Gilles and Poirier's 217.88.