Three-times Olympic champion Sun, 34, was banned from competing for four years and three months for a dope test violation in 2018 in which he and members of his entourage smashed vials containing blood samples.
The ban, reduced from the original eight years on appeal, expired in May 2024, though Sun missed national trials for the Paris Games due to the suspension. Sun, who represents Zhejiang province, said he has no plans to retire any time soon.
He sits eighth heading into the final after an impressive semi-final swim of 1:48.30, trailing 18-year-old leader Zhang Zhanshuo by 1.41 seconds.
Sun previously won the men’s 400 metres freestyle title last year at the National Summer Swimming Championships in Hefei after returning from the four-year ban. “Every race is the best test of my current form,” Sun told Chinese media.
“There’s no regret. Once a race is over, tomorrow is a new beginning. No matter if it’s young athletes or our older generation, I believe we can all move forward and go further.”
“My persistence represents the final line of defence for my generation of athletes. I hope everyone will continue to look forward to a better, more complete version of Sun Yang in the pool.” “When I was young, I wanted to win China’s first men’s swimming gold medal. Now, I want to break another barrier – to see how far an older athlete can go.”
Sun clocked 3:49.53 to finish sixth in the 400 metres freestyle, finishing 6.71 seconds behind leader Zhang, who topped the field in 3:42.82.