Tokyo Olympic silver medalist Tomoru Honda pulled away late to become Japan's first men's 200-meter butterfly world champion in Doha on Thursday.
The 22-year-old swam stroke-for-stroke against Italy's Alberto Razzetti before separating in the final meters at the Aspire Dome.
Honda touched the wall in 1 minute, 53.88 seconds, with Razzetti (1:54.65) taking silver and Austria's Martin Espernberger rounding out the podium (1:55.16). Last year's world champion, France's Leon Marchand, did not compete in Doha.
The winning time was well outside Honda's personal-best of 1:52.70, set at the Japan Open in December 2022, but the Yokohama native was pleased with the result in light of a recent ankle sprain that reportedly still causes pain when he kicks.
"All I can say is that I am happy," said Honda, who took bronze at the two previous world championships.
"I've had ups and downs, but I feel as though I could push through them to achieve my goal of winning gold. I'm hopeful of setting an even better time without any injuries."
Daiya Seto advanced to the final of the men's 200 individual medley with the fourth-fastest semifinal time of 1:57.85. American Carson Foster was in pole position after clocking 1:57.13.
Seto, the former 400 IM world champion, said he aimed to replicate Honda's performance in the final.
"It makes me want to do my best as well," he said.