Sun Yang's first title after the ban came on the 400 meters freestyle, which he won with a time of 3.49,58 – just over nine seconds above the Olympic gold time from London 2012.
I feel rusty, so I need more competitions, said China's most successful swimmer afterwards.
The 32-year-old Sun Yang has won three Olympic golds and eleven World Championship golds in his career.
The Chinese swimmer also became emotional and shed tears in front of reporters afterwards, saying, according to South China Morning Post:
It's the trust and support from my family that has made me come back.
Sun Yang was banned in a highly publicized verdict in 2021 for four years (counting from 2020) by the Court of Arbitration for Sport (Cas) after he refused to provide a doping test when he was to be tested at his home.
The incident occurred in 2018, and he was initially acquitted by the International Swimming Federation before being convicted by Cas.
Sun Yang was also banned for three months in 2014 for taking a prohibited substance.
His ban expired in May this year, but too late to qualify for the Olympic Games in Paris.
Sun Yang's comeback comes shortly after another Chinese doping controversy. In the spring, it was revealed that 23 Chinese swimmers had failed doping tests ahead of the Olympic Games in Tokyo 2021.
The World Anti-Doping Agency (Wada) and the International Swimming Federation accepted China's own explanation that the small amounts of the heart medication trimetazidine that had triggered the tests had come from contaminated food, and the swimmers were acquitted.
