Reigning Olympic champion Shohei Ono won his third title in the men's 73-kg division at the World Judo Championships on Tuesday, while fellow Tsukasa Yoshida settled for silver in the women's 57-kg class.
Ono defeated Azerbaijan's Rustam Orujov in the final with an uchimata inner-thigh sweep for ippon, less than two minutes into the bout at Nippon Budokan, the venue for judo at the 2020 Tokyo Olympics.
Japan has claimed three gold medals from six divisions for men and women combined after three days of action.
The 27-year-old Ono, competing at his first world championships since 2015, won all six of his matches by ippon. He beat Russia's Denis Iartcev in the semifinals.
Ono took time off judo after winning the 2016 Rio de Janeiro Olympics in order to concentrate on his studies in graduate school and returned to competition last year.
Iartcev and Azerbaijan's Hidayat Heydarov earned bronze.
In the women's 57-kg final, Yoshida lost to her longtime rival and Japan-born Christa Deguchi of Canada in extra time.
Yoshida started aggressive and attempted many techniques, but Deguchi resisted and scored a waza-ari for her maiden world championship.
The 23-year-old Deguchi was born and raised in Japan but decided to represent her father's home country to increase her chances of competing at the Summer Olympics. She earned bronze in her world championship debut last year.
"I knew I would have to face Deguchi in the final. I wanted to pick up the momentum, but I wasn't good enough," Yoshida said.
"I want to compete against her in the finals of the Tokyo Olympics. It will be my turn to win."
Joshiro Maruyama and Uta Abe won the men's 66 kg and women's 52 kg, respectively, on Monday, the second day of the week-long tournament.