Daiya Seto, who captured Japan's only gold medal of the just-concluded world championships in the men's 400-meter individual medley, won the same discipline Wednesday on the first day of a short-course World Cup swim meet.
Seto came home in a winning time of 4 minutes, 0.37 seconds, but the 19-year-old could only manage fifth in the 200 butterfly in 1:51.90 and failed to qualify for the 200 breaststroke final.
"To be honest I was looking to set a personal-best time (in the 400 medley) so I am a bit disappointed that couldn't go faster," said Seto. "My body was a bit heavy over the first half of the race.
"The world championships are over now so I am just looking forward now and trying to do my best."
Aya Terakawa, winner of two bronze medals at the worlds, won the women's 50 backstroke in 26.20. Kosuke Kitajima was sixth in the men's 50 breaststroke in 26.83.