Having secured three gold medals on the opening day of the three-day Grand Prix, home fans were primed for further success with Sainjargal having reached the final due his semi-final opponent and Olympic champion Mansur Isaev of Russia opting to withdraw from the competition due to fatigue.

Olympic bronze medallist Sainjargal was expected to have an easy ride to the title but understimated Sai, who had displayed impressive from throughout the event.

His victory over Sainjargal's compatriot Miyaragchaa Sanjaasuren in the semi-final should have highlighted his danger, despite being ranked as the world number 88.

Sai showed little sign of nerves in the gold medal bout, despite competing for his first Grand Prix title, attacking his rival throughout the contest before delivering a stunning ippon to claim victory.

There was more success for China in the division at Mongolia's expense as Sun Shaui claimed one of the two bronze medals on offer, beating Sanjaasuren via an ippon.

In the absence of Isaev, Mongolia's Odbayar Ganbaatar secured the second bronze.

Mongolia may have tasted disappointment with Sainjargal's defeat but were able to celebrate a gold medal from Tserennadmid Tsend-Ayush in the women's under 63kg event.

She repeated her performance of two years ago when she claimed the Ulaanbaatar Grand Prix title.

Tsend-Ayush was tested by world junior champion Miho Minei in the gold medal bout, but saw off her Japanese opponent with a waza-ari, the only scoring move of the contest.

Austria's Bernadette Graf continued her recent fine form, including securing a bronze medal at the European Games in Baku, defeating China's Chao Zhou to clinch gold in the women's under 70kg event.

Graf had progressed to the final with an ippon on Germany's Iljana Marzok her semi-final and did it again in the final, sealing victory with 12 seconds remaining, although she already had the advantage having scored with a yuko.

The bronze medal matches also produced a historic moment for Angola's Antonia Moreira as she claimed her country's first-ever medal on the World Judo Tou, beating France's Fanny Estelle Posvite.

The second bronze was won by Germany's Iljana Marzok after she beat Morocco's Assmaa Niang with an ippon.

Canada's Antoine Valois-Fortier earned the final gold medal of the second day of competition - and his first on the Grand Prix circuit - after he was awarded the under 81kg gold medal bout over Hungary's Attila Ungvari because he received less penalties than his opponent after a scoreless encounter.

Iran's Saeid Mollaei earned the first of the two bronze medals with a victory over Germany's Dominic Ressel, while Dagvasuren Nyamsuren claimed bronze by winning an all-Mongolian tie against Uugganbaatar Otgonbaatar due to a shido, after the bout had ended scoreless. 

The third and final day of the Grand Prix is due to medals decided in the women under and over 78kg categories while the men's over and under 100kg divisions will also be decided, as well as the under 90kg event.

Watch the latest action on Judo TV here

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