
Ex-Manchester City player Teerasil Dangda put the home side in front with a fine individual effort inside the box in the 12th minute before midfielder Suchao Nutnum extended the advantage eight minutes later.
The Middle East side halved the deficit early in the second half before the game ended in controversy, which saw the visitors walked off the pitch in protest on two occasions following the brawls involving Sukha twin brothers and Lebanon's Zakaria Charara.
Thailand will face Denmark, who beat North Korea 1-0 in the other match, in the Friday's final of the annual tournament.