"The nerves are different from last year, when you’ve won it before, you’ll wonder if you can do it again," he said.

"That becomes a kind of stress and it can really affect your training, I hope I don’t put too much pressure on myself and just face the competition as normally as I can."

He crashed on his first routine before producing an impressive performance on the first day of qualification to score 60.690.

Yan is part of a strong Chinese contingent which includes Olympic women's individual champion Zhu Xueying.

She scored 56.080 but it was her compatriot Hu Yicheng who led the standings with 56.600.

2021 world gold medallist Bryony Page from Britain is currently fifth after a score of 55.700 but also through to the next stage.

Megan Healey of Britain won individual gold last year in the tumbling and achieved qualification with 48.300. 

Her 17-year-old compatriot Comfort Yeates is top of the leaderboard with 51.100.

Team tumbling is scheduled for the first day of medal competition tomorrow.

In all 15 world titles are set to be decided at the Arena Sofia.

World Games men’s tumbling champion Kaden Brown of the United States is hoping for an unusual double gold after his victory in Birmingham in July.

Sweden’s three-time double mini trampoline (DMT) world champion Lina Sjöberg is expected to bid farewell to the event over the next three days to concentrate on trampoline.

"I’ve been focusing mainly on DMT and I do trampoline on the side," Sjöberg said.

"Now I feel like there is a lot more for me to achieve in trampoline, and there is not that much more to achieve in DMT, so I’ve made up my mind - I’m going to focus on trampoline and see where it goes."

Sjöberg scored 50.000 to place ninth in the first round of qualification.

2021 world bronze medallist Melania Rodriguez leads the standings with 52.800.