Olympic champion Kosuke Hagino faces a fierce challenge from close to home in the 400 metres individual medley at this summer's world championships after a chastening loss in the Japanese nationals.
Hagino, who ended 20 years of American dominance of the event by winning gold in Rio last year, was touched out by reigning world title holder Daiya Seto in Thursday's final in Nagoya, denying him a sixth successive crown.
"I only lost by one hundredth, it was a tough race," local media quoted Hagino as saying Friday. "But it gives me extra motivation. I should be able to kick on from this."
Hagino, competing in only his second meet since undergoing elbow surgery last September, clocked a pedestrian four minutes, 10.45 seconds.
"That's four seconds off my best time," added the 22-year-old, who beat American Chase Kalisz into second with Seto taking bronze at the Rio Olympics.
"I pushed as hard as I could. But Daiya deserves credit because he's kept improving since Rio and become an even better swimmer."
Hagino also goes in the 200m individual medley, the 200 and 400m freestyle and the 200m backstroke as he looks to recover his race sharpness in time for the world championships in Budapest this July.
"There's still time," said Hagino, who also took silver in the 200m medley behind Michael Phelps in Rio. "I think I'll be able to get myself ready."
Seto, who is targeting a world treble in the 400m individual medley, said: "This title has boosted my confidence. Hopefully I can get close enough to dead-heat with Kosuke at the world championships too."