Two of the goals were scored by Van Nam while the other was made by Viet Anh.
With this third win, Vietnam’s U18 football team has nine points, consolidating its top place in Group B thanks to better goal difference than Indonesia.
At a match with the hosts Myanmar two days later, Vietnam will only need a draw to enter the semi-finals of the regional tourney.
Earlier, the team had thrashed Brunei 8-1 and the Philippines 5-0.
At the tournament, U18 Vietnam is in the same group with Indonesia, Brunei, the Philippines, New Zealand and Myanmar.