A Brunei team that was comprised predominantly of students was always going to find life tough against Vietnam, despite Toshiya Miura not fielding a full strength side, and while Brunei put on a valiant display they were completely outplayed.
The first half heralded just one goal despite Vietnam's dominance, with Le Thanh Binh finding the back of the net in the 25th minute.
Phi Son Tran then added a second just two minutes into the second period when he headed home a Nguyen Cong Phuong free-kick. Cong Phuong had a chance to get his name on the scoresheet in the 62nd minute, but his penalty attempt was saved by goalkeeper Ahsanuddin.
It was then that the floodgates opened, with Vietnam getting their third goal in the 75th minute when replacement Mac Hong Quan found his way past Ahsanuddin.
Duc Huy Pham then grabbed the fourth in the 78th minute before Cong Phuong made it 5-0 four minutes later.
Captain Pham Manh Hung rounded off the scoring in the penultimate minute of normal time, with his strike from distance getting the better of Ahsanuddin.