Hifumi Abe and Yuma Oshima secured titles on the first day of the Judo Grand Prix event on Thursday.
Abe, the 18-year-old 2014 Youth Olympic Games gold medalist, beat China's Ma Duanbin by ippon in the 66-kg category, taking just 36 seconds to win his final bout. It was the fifth fight Abe won by ippon at the Grand Prix.
Oshima's victory over Uzbek, Sharafuddin Lutfillaev, also came via ippon.
Still to represent for Japan at the Tashkent Grand Prix are Kenta Nagasawa (90 kg), Kenta Nishigata (over-100 kg) and Aaron Wolf (100 kg).