Khoi entered the standard chess competition as the top seed with an Elo rating of 2,516. He trounced his rival after 36 moves.
Earlier, he put up a terrific display to win the rapid title.
Following the championship, Khoi has an Elo rating of 2,754. Anyone with Elo rating upwards of 2,700 is considered a Super Grandmaster.
The 2019 Asian Junior Chess Championship takes place in Solo, Indonesia on July 2-8, and features three categories of rapid, blitz and standard chess.
This year’s event attracted 34 male and 36 female from Bangladesh, Hong Kong, Indonesia, India, Iran, Kazakhstan, Malaysia, New Zealand, the Philippines, Taiwan and Vietnam.
Excellent chess players include Alireza Firouzja with Elo rating of 2,685, Parham Maghsoodloo with 2,656 and Nihal Sarin with 2,610.
