The Singaporeans had looked the more likely to score as a tepid opening 45 minutes slowly came to life, with Ilhan Fandi seeing his free kick kept out by Kampon Phatomakkakul before the Thai keeper tipped a second attempt, this time a header, over the bar.

Song Ui-young should have put the visitors in front two minutes before the interval when Farhad Zulkifli’s cutback from the right found the midfielder unmarked inside the penalty area but his first-time strike was saved by Kampon.

Less than two minutes later, though, the Singaporeans went in front. Kampon raced out of the penalty area to prevent Farhad racing towards goal, only for the ball to land at the feet of Stewart and his first-time strike sailed into the empty net.

Thailand levelled just after the hour mark when Kakana Khamyok thumped his penalty into the top corner of the Singapore goal following Rhyan Stewart’s poorly judged tackle on Wanchai Jarunongkran but within four minutes the Lions were back in front.

The home defence laboured in their efforts to clear the ball, which ended up at the feet of Rhyan Stewart and his low shot was deflected past Kampon via the shin of the unfortunate Pansa Hemviboon.

Teerasak Poeiphimai was denied opportunities to level for the Thais, the Port FC striker hitting the post in the 65th minute before seeing Izwan Mahbud make a fine save as time ticked down.

But Thailand’s two-goal cushion from the first leg on Saturday was to prove enough to take the War Elephants into a 12th ASEAN Championship final in 16 attempts.