Four goals from Saowalak Pengngam and a hat-trick from Jenjira Bubpha helped Thailand claim its first victory in the competition.
Sara Zohrabi scored Iran’s only goal in this match.
Iran, who has suffered back-to-back losses against Korea Republic and DPR Korea, finished in fourth place in the group.
“We prepared well for this game and played well. It was nice to score a goal, but I wanted more from them,” said Iran coach Mahnaz Amirshaghaghi.
“This tournament has been a very good experience and we are very happy to be here. We have to learn from the teams that we have played here because they will help us develop; we want to be able to challenge them one day.”