Japanese judoka won four of the seven gold medals on offer on the opening day of the Paris Grand Slam judo tournament on Saturday.

Wakana Koga, who took the women's 48-kg silver at the world championships in June, defeated France's Melanie Legoux Clement by ippon in the final of her weight class for Japan's first gold in the 50th edition of the International Judo Federation event.

In the men's 66-kg final, 19-year-old Ryoma Tanaka came out on top, beating fellow Japanese Taikoh Fujisaka in another ippon victory at AccorHotels Arena.

Kenshi Harada won the men's 73-kg title, and Haruka Funakubo secured the women's 57-kg title by winning all four of her bouts by ippon.

Genki Koga, the son of the late legendary judoka Toshihiko Koga, finished fifth in the men's 60-kg.

Soichi Hashimoto, the world champion at the men's 73-kg in 2017, and Ryoko Takeda, competing in the women's 52-kg, were both eliminated in the second round.

The two-day Paris Grand Slam, featuring 45 countries and 281 judoka, is the first international event for Japan's judo team since the Tokyo Games. No athletes who took part in the Olympics this summer are competing.

It is also the debut competition for new men's head coach Keiji Suzuki. An Olympic and double world champion, Suzuki replaced Kosei Inoue earlier this month. Inoue retired after two terms spanning nine years at the helm.