Tomoko Hagiwara became the first swimmer in the history of the national championships to win four titles in a single meet when she won her first women's 100-meter freestyle crown Sunday.

Hagiwara of Yamanashi Gakuin University won the race at the Tokyo Tatsumi International Swimming Center pool in 55.13 seconds for the second-fastest time ever by a Japanese swimmer.

"I really didn't practice for this race, but I figured that all I needed was to flip over and have the other side of my body facing up," said Hagiwara, generally regarded as a backstroke competitor.

"I'm happy that I was able to post my best time," Hagiwara said after pulling away from freestyle specialist Tomoko Nagai to win by 0.68 second in her 12th race in six days. Hagiwara earlier won the 200-meter backstroke, 200-meter individual medley and the 200-meter freestyle.

World bronze medalist Kosuke Kitajima, meanwhile, won his third championship of the meet by taking the men's 100-meter breaststroke in 1 minute, 0.63 seconds -- just 0.02 second outside of his own national record time. Kitajima had earlier won the breaststroke at 200 and 50 meters.

In the men's butterfly, Takashi Yamamoto also scored the triple crown when he won the 200-meter event in 1:56.54. In the men's 50-meter backstroke, Atsushi Nishikori set a national record, winning in 25.96 seconds.