Australia will now take on host nation Myanmar on Thursday in the playoff for third spot in the tournament.
Despite making nine changes to the side that played the final group match, the Young Matildas made the perfect start in the semi and took the lead inside 11 minutes.
Grace Maher intercepted a pass out of Thailand’s defence before surging towards goal and showing great composure to score.
But the stifling heat made it hard for Australia to get any rhythm and Thailand hit back with two goals before the break, including a penalty.
Only some excellent saves from keeper Hannah Southwell and the woodwork saved Australia from falling further behind in the second half as Thailand increased the pressure.
While coach Craig Deans made a few substitutions to try and find the equaliser, Thailand held firm to keep the Young Matildas at bay.
Despite missing a spot in the decider, coach Craig Deans was delighted with the squad’s exploits at the tournament.
“We obviously wanted to try and make the final but most importantly the tournament was an opportunity to play games under pressure against good opponents, which we have been able to do,” Deans said.
“We now have one more game in the 3/4 playoff to see where we are at as a squad.
“The whole tournament has provided valuable experience for a playing group that is largely inexperienced at international level. We have learnt valuable lessons and will continue to strive for improvement.”