A marathon fightback failed to lift Thailand to Group I of the Davis Cup Asia/Oceania Zone as they went down 3-2 to Pakistan in Islamabad yesterday.
The result means that Thailand will be spending at least another year in Group II of the competition.
Having closed to gap to 2-1 after Saturday's doubles match victory from twins Sonchat and Sanchai Ratiwatana, the Kingdom's stars needed two wins yesterday to earn the promotion while the hosts only required one victory to earn a spot in Group I next year.
Top-ranked Thai Wishaya Trongcharoenchaikul raised Thailand's hopes after a thrilling 7-5, 7-6 (7/4), 4-6, 6-7 (3/7), 7-6 (7/3) win against Pakistan No.1 Aisam Qureshi in the first reverse singles on the outdoor grasscourts at Pakistan Sports Complex.
The victory sent the tie into the decisive fifth rubber.
No.2 Kittiphong Wachiramanowong was unable to match his teammate as he lost to Aqeel Khan 4-6, 3-6, 6-3, 6-2, 2-6.
Aqeel proved too strong for a visibly tired Kittiphong who did remarkably well to push the match to five sets after having lost the first two.
Thailand had been left on the brink after conceding the first two singles rubbers to Pakistan on Friday.
Sonchat and Sanchai won the doubles match against Shahzad Khan and Muhammad Abid on Saturday to keep the tie alive after both Wishaya and Kittiphong lost their opening singles on Friday.
Thailand were relegated from Group I after losing to China in a play-off tie in 2015. They lost to Taiwan in last year's play-off.
AUSTRALIA, FRANCE ON BRINK
Australia edged closer to a first Davis Cup final in 14 years on Saturday when Jordan Thompson and John Peers swept past Arthur De Greef and Ruben Bemelmans 6-3, 6-4, 6-0 for a 2-1 lead in their World Group semi-final against Belgium in Brussels.
Australia, the 28-time champions, look likely to face nine-time winners France who are 2-1 up on Serbia thanks to Nicolas Mahut and Pierre-Hugues Herbert clinching a 6-1, 6-2, 7-6 (7/3) win over Nenad Zimonjic and Filip Krajinovic.
Lleyton Hewitt's Australia last won the Davis Cup in 2003 when they beat Spain in the final.
In Lille, Mahut and Herbert needed less than two hours to see off Serbia's 41-year-old playing captain Zimonjic and Krajinovic.
That Yannick Noah's hosts have yet to book their place in the final is down to Dusan Lajovic's shock 6-1, 3-6, 7-6 (9/7), 7-6 (7/5) win in Friday's opening rubber against Lucas Pouille, although Jo-Wilfried Tsonga had levelled the tie by beating debutant Laslo Djere 7-6 (7/2), 6-3, 6-3.
Mahut and Herbert, the 2015 US Open and 2016 Wimbledon champions, came back from 5-2 down in the third set to wrap up the win.
France are bidding for a first Davis Cup title since 2001, having lost three finals since with the most recent a defeat by Roger Federer's Switzerland in 2014.
Last year's Davis Cup champions Argentina were knocked out of the competition's top tier yesterday following a shock defeat to Kazakhstan.
Mikhail Kukushkin defeated Diego Schwartzman 6-4, 6-4, 7-6 (7/2) in a battle between the teams' top-ranked players to give Kazakhstan an unassailable 3-1 lead in the best-of-five match in Central Asia.
Schwartzman, who as the 28th-ranked player is 50 places above Kukushkin, lost his first two service games in each of the first two sets and struggled to recover.
Argentina -- which didn't have their top-ranked player Juan Martin Del Potro in Kazakhstan -- are the first reigning Davis Cup champions to be relegated since Sweden in 1999.
Argentina was last outside the top-tier World Group in 2001, while Kazakhstan return following relegation last year. -- Bangkok post/agencies