Former Thailand striker Teeratep Winothai's testimonial match on Wednesday night ended in "a big disappointment" for the War Elephants as they were beaten 1-0 by Taiwan in a friendly at Thammasat Stadium.
The match also served as the last warm-up for the Thai national team before the start of their title defence at the AFF Mitsubishi Electric Cup which kicks off on Tuesday.
Chen Jui-chieh grabbed the winner for Taiwan in the 72nd minute after Teeratep had been replaced by Poramet Arj-vilai late in the first half.
Thailand coach Mano Polking admitted after the match that result had been "a big disappointment for everyone in the team."
"However, I am happy that we were able to test every player in these two warm-up games," he added, also referring to a friendly with Myanmar which the War Elephants won 6-0 on Sunday night at the same venue.
"After seeing all these players in action, we now have a clear idea about our weaknesses and our plans for the AFF Mitsubishi Electric Cup," said Polking, who rested a large number of regular starters on Wednesday night.
Defending champions Thailand are in Group A along with Brunei, Cambodia, Indonesia and the Philippines for the first-round competition of the tournament, which is the Southeast Asian championship.
Meanwhile, an emotional Teeratep said: "It was an honour to play for the Thai national team.
"This was my last football game as a player. I hope that the current national team players will do their best in the Asean championship and I wish them all the best."
