Thailand lost to hosts New Zealand 3-1 in the Davis Cup World Group II tie at Invercargill on Saturday.
After losing both singles matches on the opening day, Pruchya Isaro and Wishaya Trongcharoenchaikul went down Finn Reynolds and Artem Sitak 6-4, 6-2 in the doubles tie as New Zealand claimed the third point to win the tie.
Thai-Australian Maximus Jones won the third singles match against Isaac Becroft, who replaced New Zealand No.1 Rubin Statham, 6-3, 3-6, 10-8 to win a point for Thailand.
It was the first Davis Cup win for Jones, who made his debut in the tournament.
With the victory, New Zealand will compete in the 2024 World Group I play-off round while Thailand will compete in the 2024 World Group II play-off.
"Overall, the team did well but we have to accept that New Zealand had the advantage of playing at home," said captain Thanakorn Srichaphan.
"Their doubles players were once ranked 32nd in the world and their experience showed during the match. Pruchya and Wishaya gave their all and tried to hold their service games but their opponents were simply on a higher level.
"Rubin Statham especially is a very experienced guy."
"However, we would like to thank our supporters who came to cheer our team at the venue. We will try to stay in the World Group II when we play in the World Group II play-off next year," he added.
On Friday, Thailand No.2 Kasidit Samrej was beaten 6-2, 7-6 (10/8) by Statham while Jones lost to Ajeet Rai 6-1, 6-3 in the first and second singles matches.