The match, at the National Stadium in Singapore, was dominated by Vietnam, who scored four goals in the first-half including a brace by Vo Huy Troan.
In the 13th minute Vietnam went a goal up when they were awarded a penalty for a handball by Hansamu Yama Pranata in the area.
Mac Hong Quan stepped up to take the spot-kick and give his side the lead.
Eight minutes later they doubled their lead when Vo broke through the defence to beat goalkeeper Teguh Amiruddin and make the score 2-0.
Vo then got his second goal in the 41st minute when he hammered a shot from around 25-yards out to beat the keeper and score.
Then just before the half-time break Nguyen Huu Dung scored the fourth goal with a volley.
The final goal was scored by captain Que Ngoc Hai in the 71st minute to make the score 5-0 and in turn win the bronze medal.
In Monday’s gold medal match Myanmar face Thailand.