
Thailand took the lead through Caelan Ryan’s strike in the fourth minute before G Pavithran equalised for Harimau Muda in the 48th minute through a penalty kick.
Juan Torres Gorrido’s charges move into the last four despite failing to keep their winning streak going after emerging victorious in their first two matches.
Malaysia and Thailand both have seven points but the former topped the group on goal difference.
Singapore are third with three points and Brunei are last with zero points.
In the semifinals on Saturday, Malaysia will meet hosts Indonesia, who topped Group B with maximum points from three matches.
Malaysia opened their campaign by thrashing Brunei 11-0 on July 19 before beating Brunei 5-0 on Tuesday.