Ryosuke Irie obliterated his own short-course Japanese record to win the men's 200-meter backstroke the opening day of the short-course national championships on Saturday.
Irie, who finished fifth at last summer's Beijing Olympics, romped to his first title in 1 minute, 49.92 seconds, slicing 1.42 seconds off the mark he established at a World Cup meet in Berlin last November.
Ryo Tateishi shaved .07 off double Olympic champion Kosuke Kitajima's record to win his first men's 100-meter breaststroke crown in 57.55 as a total of 15 new short-course national marks were set at Tokyo Tatsumi International Swimming Center.
Among the record breakers were Hanae Ito, winner of the women's 200-meter backstroke in 2:03.01, fellow Beijing Olympian Asami Kitagawa and Hiroki Kato.