Daiya Seto won the men's 200-meter individual medley at the world championships on Thursday and became the first Japanese swimmer to book a ticket for next summer's Tokyo Olympics.

Seto topped a podium at the worlds for the third time in his career after clocking 1 minute, 56.14 seconds in the eight-man field in South Korea. He finished 0.42 second ahead of Jeremy Desplanches of Switzerland.

Not only did Seto become the first Japanese world champion in the 200 IM, but he tied four-time Olympic breaststroke champion Kosuke Kitajima for the most worlds gold medals by a Japanese swimmer.

The 25-year-old Seto was world champion in the 400 IM in 2013 and 2015, before slipping to bronze in 2017.

"Since I lost in 2017, I've been trying different things, and little by little those challenges have paid off," Seto said.

"My condition is really good. I had also been aiming for gold in the 200, since I got here and saw how things were and how well I was swimming, I thought I could swim a personal best."

He claimed silver in the 200-meter butterfly on Wednesday, finishing behind new world record holder Kristof Milak of Hungary.