Mixed doubles duo Dechapol Puavaranukroh and Sapsiree Taerattanachai lost to Tang Chun Man and Tse Ying Suet of Hong Kong 21-12, 21-12 in the quarter-finals of the US$1 million China Masters on Friday.
The fifth-seeded Thais were no match for the unseeded opponents at Shenzhen Bay Gymnasium.
The setback ended Thailand's interest in the World Tour Super 750 tournament.
Dechapol, 26, and Sapsiree, 31, have not won since their victory at the Malaysia Masters in May.
They have since reached two more finals but lost at the Thailand Open and Japan Open.
In the men's singles quarter-finals in Shenzhen on Friday, Kenta Nishimoto of Japan beat Lee Zii Jia of Malaysia 21-11, 21-12.
Nishimoto, who upset Thailand's Kunlavut Vitidsarn in the round of 16, will face China's Zhao Junpeng in the semi-finals on Saturday.
Zhao defeated Taiwan's Lin Chun-yi 18-21, 21-17, 21-15 in the last eight on Friday.
Meanwhile, the richest tournament in badminton has become even richer after the sport's governing body ramped up the prize pot for the season-ending BWF World Tour Finals to $11.5 million over the next four years.
The prize money for this year's Finals, taking place from Dec 13-17 in the Chinese city of Hangzhou, will be $2.5 million, up from $1.5 million last year.
It will increase over the coming years to $3.5 million in 2026, the Kuala Lumpur-based Badminton World Federation said.