Japan's Wakana Koga was among the four winners on the opening day of the 2019 IJF World Junior Championships in Marrakech ©IJF/Di Feliciantonio Emanuele

Japan's Wakana Koga was among the four winners on the opening day of the 2019 International Judo Federation (IJF) World Junior Championships in Marrakech.

The 18-year-old beat France's Shirine Boukli in the women's under-48 kilograms final at the Moroccan city's Chapiteau - Quartier Agdal.

It comes just over three months after she upset the odds to triumph at the IJF Grand Prix in Montreal, defeating Olympic champion Paula Pareto of Argentina en route to the final.

Serbia's Andrea Stojadinov and North Korea's Jon Su Song were the women's under-48kg bronze medallists.

In the women's under-52kg final, Mongolia's Sosorbaram Lkhagvasuren overcame Chinese Taipei's Hsu Lin Hsuan. 

The bronze medals went to Japan's Ayumi Kawada and Brazil's Larissa Pimenta.

Russia's Konstantin Simeonidis came out on top in the men's under-60kg category ©IJF/Mayorova Marina
Russia's Konstantin Simeonidis came out on top in the men's under-60kg category ©IJF/Mayorova Marina

Two men's events were also held, with Russia's Konstantin Simeonidis beating Azerbaijan's Ahmad Yusifov in the under-60kg final and Brazil's Willian Lima defeating Japan's Takeshi Takeoka in the under-66kg final. 

Rounding off the under-60kg podium were Japan's Ken Suematsu and Turkey's Salih Yildiz.

Azerbaijan's Ibrahim Aliyev and Brazil's Michael Marcelino were the under-66kg bronze medallists.

Competition in Marrakech continues tomorrow.

Medals will be awarded in the women's under-57kg, women's under-63kg and men's under-73kg categories.

Watch all the action on Judo TV.