The 20-year-old Ly, the first player from Vietnam to win an ITF title after he won a trophy on homesoil last year, managed a crucial break for a 3-2 lead in the final set which was enough for him to clinch the win 2-6 7-6 (7-5) 6-4 after two hours and 24 minutes.
Currently at No 529 in the world, the Vietnamese young gun will crack the top 500 when points are added in the ATP computer system in the next two weeks.
Ly, the former junior Wimbledon doubles finalist, is the heavy favourite to win the men’s singles gold medal when the SEA Games starts in Malaysia this August.
The next three ITF Men's Futures in Thailand will take place at the Lawn Tennis Association of Thailand in August.