"Her kicking was great — she just whooshed forward. She wasn't scared to jump in, and even when the water covered her head, she wasn't afraid."

With her father's agreement, Yu began formal training.

Her rise was swift and steady: she joined the provincial training team at age nine and began competing at the national level at 10.

She garnered wider attention during the National Swimming Championships in May, where she won the 400m individual medley and the 200m butterfly.

She achieved the A standard in all three of her events, qualifying for the world championships and quickly attracted global attention.

At the Singapore worlds, the youngest athlete in the entire competition became one of its most talked-about. Yu reached the finals in all three of her individual events and finished fourth in each.

She also swam in the preliminaries of the women's 4X200m freestyle relay, helping China win a bronze medal — making her the youngest medalist in the history of the world championships.