Marc Klok fired Indonesia into the lead in the 48th minute from the penalty spot after Theerathon Bunmathan’s handball earned a yellow card.
Things looked bleak for defending champions Thailand when Sanrawat Dechmitr was shown a straight red for hacking down a home player in the 63rd minute. But the depleted War Elephants roared back with Sarach Yooyen's strike from the edge of the area with 11 minutes left in the match.
Thailand remain top of Group A with Indonesia in second on goal difference. Cambodia cemented their grip on third place in the group with a 5-1 thrashing of Brunei in Phnom Penh to keep alive hopes of a top-two finish and a place in the semi-finals.
Thailand next play Cambodia at Thammasat University on Monday (kick-off 7.30pm). Fans can watch the match live on MCOT HD30 and T-Sport 7 channels.
Thailand’s manager Mano Polking praised his players for salvaging a draw after going a goal behind and losing one man. He added that the referee had made the right decision in sending off Sanrawat as the tackle clearly deserved a red card.