Pham Thi Tuoi opened the scoreboard for Vietnam in the second minute, but Siranya Srimanee levelled the score for Thailand in the 18th minute. Sasicha Phothiwong secured the match-winner with just two minutes left on the clock.
After three group losses, Vietnam said goodbye to the event's semi-finals.
"We were nervous in the first half because we needed to win to proceed to the semi-finals and our opponents scored first goal. But we had planned and prepared for such a situation and my players followed what I asked of them well," said Thailand's coach, Rakphol Saintengam, on the-afc.com.
Vietnam's coach, Truong Quoc Tuan, also spoke positively, "I think we played pretty well even though we lost. We created many chances to score but had problems finishing. This is something we have to improve in the future. It was a very good lesson for our next tournament."
Japan, the three-time Asian Indoor Games gold medalist, topped Group B after crushing China 7-1. Japan and Group B runners-up Thailand earned a ticket to play in the final four on September 25.
The event's final match will take place on September 26.-VNA