Kazakhstan's Nurkanat Serikbayev was among the winners on the opening day of the World Judo Championships Cadets in Almaty.
The home fighter won the men's under-50 kilograms category at the Baluan Sholak Sports Palace, beating France's Romain Valadier Picard in the final.
Serikbayev first scored waza-ari and completed his victory with osaekomi.
"My coach told me before the final to control his right hand and to do my judo," he said.
"This is exactly what I did.
"I managed to execute ura nage first and I finished the job with osaekomi.
"To win at home in such a nice way is just amazing."
The bronze medals were won by Ukraine's Mykyta Holoborodko and Georgia's Nika Bachiashvili.
The first gold medal of these Championships for competitors under the age of 18 was won by Hungary's Luca Mamira, who beat Italy's Chiara Antonina Dispenza in the final of the women's under-40kg category.
France's Pauline Cuq and Kazakhstan's Alima Zhumagaliye won the bronze medals.
Turkey's Merve Azak claimed the gold medal in the women's under-44kg, defeating Venezuela's Summer Youth Olympic Games champion María Giménez in the final.
In a close contest, Azak took the lead with a waza-ari in the final minute and secured the title.
"I knew her strongest move is harai-makikomi," she said.
"I was prepared to face her and did exactly what I have planned with my coach."
Brazil's Laura Soken and Japan's Miyagi Ayuna claimed the bronze medals.
Unusually, Japan finished the day without a gold medal after Chinese Taipei's Lin Chong-Yu won the men's under-55kg.
He beat Japan's Sato Yuma with a fast arm lock move.
Uzbekistan's Sobirjon Karimov and Italy's Vincenzo Skenderi won the bronze medals.
Action is due to continue tomorrow.