Panut Kittipanuwong drew first blood for Thailand in just the second minute when he slid the ball through the legs of Firuz Bozmamadov who was in the post for Tajikistan.
In 28th minute of the second half, Tajikistan scored their equaliser through Vositzoda Iqboli who slid to connect home a low cross from the right. The central Asian team went ahead 2-1 in the 34th minute through Idris Yorov.
Thailand responded quickly and scored the equaliser through Jetsada Chudech in the next minute.
In the last minute of the game, Worasak Srirangpirot slammed home the winning goal, sending Thailand into the semi-finals for the eighth time in 16 tournaments.
Thailand will face Iran in the semi-finals on Thursday from midnight onwards (Thailand time). The match will be broadcast live via Eleven Sports, which can be subscribed to at https://elevensports.com/th, and AIS PLAY, available for free for AIS customers here.