The eight-year-old’s medal came somewhat as a surprise since he has never done anything at the national level so far.
His family sent him to the championship held in Weifang, Shandong Province, China, at its own cost.
Duy finished third after losing to Artem Lebedev of Russia and Dinmukhammed Tulendinov of Kazakhstan.
The third grader at Hanoi’s Nguyen Du Elementary School could read and write at the age of two and a half and started to learn chess in January last year.
This summer he reportedly spent six-eight hours every day training.
The World Cadet Chess Championship was held in the Under 8, 10 and 12 categories for girls and boys. It was joined by 582 players from 55 countries and territories.
Vietnam sent a 22-member team and was one of six nations to win medals along with Russia, Kazakhstan, the U.S., China, and Mongolia.