A 24th-minute strike from Nguyen Tien Linh – that moved him level with 4-time winner Teerasil Dangda in the race for the top scorer award in this edition – sent Vietnam to the break with a narrow lead before goals from Poramet Arjvirai and Sarach Yooyen put Thailand in control.
Just when it seemed that the tie was leaning decisively in Thailand's favour, substitute Vu Van Thanh struck in the 88th minute to set up a thrilling second leg in Bangkok on Monday.