By Gabriel Tan at the Rajamangala Stadium
For much of the game, it looked as though the Azkals' route to the semi-finals was going to be made tougher as they struggled to break down a lethargic Vietnam outfit.
However, all that changed in the 85th minute when captain Emelio Caligdong came off the bench and coolly slotted past Duong Hong Son to hand his side all three points.
Having promised to make changes following his side's opening 2-1 defeat to Thailand by introducing Jason de Jong and Patrick Reichelt for Caligdong and Angel Guirado.
Nonetheless, it was Vietnam who created the first scoring opportunity three minutes in when Le Cong Vinh cleverly flicked the ball into the path of the rampaging Le Tan Tai, but he had to deal with the close attentions of Juan Luis Guirado and could only fire a half-volley straight at Eduard Sacapano.
Nine minutes later, Phil Younghusband wasted an excellent opportunity to break the deadlock when he was picked out unmarked inside the area by a right-wing cross from James Younghusband, only to scuff his shot wide with only Duong Hong Son to beat.
Two minutes before the half-hour mark, the Loyola Meralco Sparks striker was presented with another opening when Patrick Reichelt nodded a Paul Mulders delivery into his path, but Nguyen Gia Tu weighed in with a vital intervention to block his fierce snapshot.
By now, Philippines were starting to grab a stranglehold on the game and they had another chance in the 38th minute when Mulders forced his way down the right after good hold-up play by Phil Younghusband on the halfway line, and hit a cross-cum-shot that Hong Son had to tip over before it could sneak inside the top corner.
Five minutes after the break, Phil Younghusband threatened the opposition goal once more when he struck a first-time shot just wide after a being picked out by James Younghusband's flick-on header, before Vietnam mustered a rare effort on target nine minutes later when Tan Tai hit a piledriver from the edge of the area that was well saved by Sacapano.
12 minutes from time, Angel Guirado had a half chance to find the breakthrough when he beat his marker to an enticing delivery from Caligdong but failed to get enough power on his header to test Hong Son.
An even better chance then went begging three minutes later when Angel Guirado went on a powerful rampage down the right past two defenders and sent a low effort towards goal, only to be denied by Tran Dinh Dong who had recovered in time to make a brilliant sliding block.
Still, there was to be no denying Philippines in the 85th minute when Angel Guirado found space just outside the area and floated a lovely ball into the path of Caligdong, who calmly brought the ball down before lifting it over the onrushing Vietnam goalkeeper and into the back of the net.
There was still time for Vietnam to rescue a point two minutes later when Tan Tai forced his way down the left and into the box and unleashed a ferocious strike that had Sacapano beaten all ends up, only to see it smash into the bar and onto the goal-line before bouncing back out to safety once more.
As the final whistle blew, the joy on the Azkals' faces was clear for all to see as they kept alive their hopes of progressing to the semi-finals, while Vietnam's were left in tatters.
Vietnam: Duong Hong Son, Tran Dinh Dong, Nguyen Minh Duc (Truong Dinh Luat 82'), Nguyen Gia Tu, Nguyen Van Bien, Phan Thanh Hung, Le Tan Tai, Nguyen Trong Hoang, Pham Thanh Luong (Nguyen Van Quyet 73'), Huynh Quoc Anh, Le Cong Vinh (Nguyen Quang Hai 70').
Philippines: Eduard Sacapano, Ray Jonsson, Rob Gier, Juan Luis Guirado, Dennis Cagara, James Younghusband (Emelio Caligdong 74'), Jason de Jong, Jerry Lucena, Patrick Reichelt, Paul Mulders (Angel Guirado 55'), Phil Younghusband (Denis Wolf 66').
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