Kosuke Kitajima and Ryosuke Irie won the men's 100-meter breaststroke and 200-meter backstroke, respectively, with national records at the Japanese Short Course National Championships on Saturday.
Kitajima hit the wall in 57.34 seconds, 0.01 faster than Yuta Suenaga's December 2009 record, in his first race of the two-day event at Tokyo Tatsumi International Swimming Center.
Suenaga touched second in 57.67, while Naoya Tomita placed third in 58.36.
"It's always nice to set a national record, and I hope I can do this in the regular 50-meter pool as well," Kitajima said.
"First and foremost, I wanted to turn in a quality swim. This is a confidence boost since I won a race against Yuta and Tomita. Hopefully, I can have good races with them in the 50 and 200 meters as well tomorrow and feel good on my way back to the U.S."
The two-time double Olympic breaststroke champion, who now lives in California, led from start to finish in the day's final race in the 25-meter pool.
In the 200 backstroke, Irie broke his own record by 0.14, finishing in 1 minute, 49.78 seconds.