Four-time world champion Daiya Seto, who resigned as captain of Japan's Olympic swim team after an extramarital affair, swam a competitive race for the first time in nearly five months at the Japan Open on Thursday.

The 26-year-old avoided a ban from competing at the postponed Tokyo Olympics but was suspended until the end of 2020 as punishment for an affair that was exposed by a gossip magazine.

In September, he was photographed at a "love hotel" with a woman who is not his wife.

He advanced to the men's 400-meter individual medley final with the second-fastest time overall in the Japan Open heats. He has also entered the 200 individual medley and the 200 butterfly, which both take place on Saturday at the Tokyo Aquatics Center.

In October, Seto was handed an ethics code violation by the Japan Swimming Federation and was barred from competition and official training until the end of the year. He admitted his infidelity and apologized.

In addition to resigning as swimming team captain for the Olympics, Seto saw his image-rights agreement with the Japanese Olympic Committee and sponsorship with All Nippon Airways Co. torn up.