Olympic gold medalist Shohei Ono defeated countryman Masashi Ebinuma in the men's 73-kg division final as Japan won three gold medals on Saturday, the second day of the Dusseldorf Grand Slam.
Ono won his fourth Grand Slam gold medal by claiming a yusei victory over Ebinuma, a three-time world champion and a double Olympic bronze medalist in the 66-kg class.
"I think I did well if you only look at the results, but I didn't do so well if you actually look at my performance on the mat," Ono said. "It was difficult. It was a day that required perseverance."
Japan's Miku Tashiro and Sotaro Fujiwara beat Russian athletes in the finals of their respective weight classes.
Tashiro secured her second Grand Slam gold by beating Russia's Daria Davydova in the women's 63-kg with an ouchigari inner leg sweep for ippon. Japan's Masako Doi took bronze after beating Sanne Vermeer of the Netherlands following her semifinal loss to Davydova.
Fujiwara won the men's 81-kg competition after Russia's Aslan Lappinagov was disqualified for getting penalized on three occasions.
Japan won four of the five gold medals up for grabs on Friday. The three-day Dusseldorf Grand Slam doubles as one of the qualifiers for this summer's world championships in Tokyo.