Angelo Almendras nailed a huge kill to give the Filipinos at 2-1 set lead.
Bryan Bagunas and Almendras then conspired in the fourth set charge to help the Philippines in sweeping Pool A.
The Filipinos will go up against the No. 2 team in Pool B in the semifinals slated Thursday. Indonesia and Singapore, both sporting 0-1 records, are vying for the of the other semis berth in their bracket.
The Philippines earlier shocked titleholders Thailand, 30-28, 25-23, 25-19, last Sunday.
With its second straight loss, the Malaysians were relegated to the battle for fifth and sixth slots.
Host Myanmar beat Singapore, 25-13, 25-14, 25-11, Tuesday to became the top Pool B team with a 2-0 card. The Burmese will face the Thais, who placed second in Pool A with a 1-1 slate, in the other semifinal pairing.