In the match held at the at the Wunna Theikdi Indoor Stadium in Nay Pyi Taw, Myanmar, the Iranian team also booked a berth to contest the 2017 FIVB Boys’ U-19 World Championship in Bahrain in August.
Iran had already suffered two losses in the top-flight tournament against South Korea and China.
Ali Tabari contributed 19 points for Iran including 17 kills. Morteza Sharifi added with 14 attack hits and two ace serves. Mahdi Jelveh Ghaziani led the team in blocking with 5 kill blocks.
Chaiwat Thungkham led Thailand with 11 points.
Mohammad Vakili’s boys will face South Korea on Tuesday in the semi-final.