Tran Van Vu scored a double while Luu Quynh Toan made it 3-0 for Vietnam in the first half.
However, Said Alsbakhi Rasha gave Vietnam a fright after scoring in the 19th minute.
In the group’s first match, Lebanon defeated Palestine 11-4.
Only one team from each group goes through to the next round and Vietnam has to defeat Lebanon on June 30 to go forward.
In the women’s futsal, Vietnam lost 0-1 to Iran in their third-round match.
This defeat means there is little chance of Vietnam’s women making it through to the semi-finals. They now have only three points after three matches and play Malaysia on June 30.