Chonburi and Bangkok Glass failed to reach the AFC Champions League after defeats in their final qualifying matches last night.
Chonburi lost 3-2 to Kashiwa Reysol in Japan after extra time, while Bangkok Glass were well beaten 3-0 at Beijing Guoan in one-off matches of the third and final qualifying rounds.
Their exits mean Thai Premier League champions Buriram United are the only team from the Kingdom in the continental club championship.
At Kashiwa, the hosts got off to a fast start with Taketomi Kosuke opening the scoring after just eight minutes only for Leandro to equalise two minutes later.
The Japanese dominated for long periods making Chonburi goalkeeper Sinthaweechai Hatairatanakool one of the busiest players of the night.
Kashiwa's efforts were paid off in the second half when they were awarded a penalty and Leandro Montera da Silva made no mistake from the spot.
But the Sharks fought back and Kroekrit Taweekarn made it 2-2 to send the match into extra time.
Da Silva then finished off the Thais, who finished second in the TPL last season, in the 116th minute.
In Beijing, Song Boxuan broke the deadlock in the 17th minute as the hosts took a 1-0 lead at half-time.
In a one-sided encounter, Beijing proved much too strong for the Thai FA Cup champions with Pablo Batalla scoring twice in the second half.
In Gosford, Jiang Ning opened the scoring in the first half before providing the second-half assist for Lu Lin as China's Guangzhou R&F secured a place in Group F with an impressive 3-1 win over Australia's Central Coast Mariners.
Jiang opened the scoring after just eight minutes at Central Coast Stadium before helping round off an eye-catching move with the decisive pass for Lu to double Guangzhou's lead three minutes before the hour mark.
Josh Rose netted a spectacular own goal from inside his own half with just under two minutes remaining before substitute Glen Trifiro got a stoppage-time consolation for the home side.
Guangzhou will make their AFC Champions League debut in Group F alongside 2008 champions Gamba Osaka, 2010 winners Seongnam and Buriram.