(Reuters) - Kosuke Hagino, Japan's ironman swimmer, collected his fourth title at the national championships on Sunday.
Showing no sign of fatigue after another grueling week in the pool, the 20-year-old university student signed off by winning the 400 meters individual medley, the most exhausting race in swimming.
His time of 4 minutes 08.54 seconds was the fastest in the world this year and means he will almost start as the heavy favorite at this year's world championships in Russia.
Hagino, who also won the 200m individual medley, as well as the 200m and 400m freestyle titles, is more than two seconds clear of his nearest rival in the world rankings.
That is Japan's reigning world champion Daiya Seto, who was second to Hagino on Sunday, the final day of the Japanese trials.
Japan have assembled a deep and talented squad for the world championships, especially in breaststroke. Japan dominated the men's events and on Sunday, teenager Kanako Watanabe set the fastest time in the world this year for the women's 200m event, stopping the clock at 2:20.90.
Underlining the rising depth of Japan's swimmers, Rikako Ikee captured her first national senior title by winning the women's 50m butterfly aged just 14.