Thailand will play China in the semi-finals of the 2019 Asian Women's Volleyball Championship in Seoul on Saturday.
The Thais lost to hosts South Korea 3-1 (25-20, 23-25, 25-17, 25-21) in their final Pool E match of the second round, while China overcame Japan 3-2 (14-25, 25-11, 25-21, 18-25, 15-12) in a riveting Pool F encounter.
The Koreans will meet defending champions Japan in the other semi-final match on Saturday.
Thailand won the championship twice in 2009 and 2013. They lost to Japan 3-2 in the final two years ago when the tournament was held in the Philippines.
Asian volleyball powerhouse China have lifted the coveted trophy on 13 occasions.
Thailand started the match with an experienced line-up of Pornpun Guedpard, Chatchu-on Moksri, Onuma Sittirak, Thatdao Nuekjang, Malika Kanthong and Piyanut Pannoy.
Thailand and South Korea went into the match with a split 7-7 head-to-head record with the Thais winning four of their last five meetings.
The South Koreans, coached by Italian veteran Stefano Lavarini, are led by their superstar captain Kim Yeon-Koung and Lee Jae-Yeong as they chase their first ever continental title.
The host team got off to a strong start and took the opening set 25-20.
Thailand put on an improved show in the second set, with Onuma and Malika scoring some key points as the Koreans made too many errors.
Backed by a vocal and energetic home crowd, South Korea rebounded to take the third and fourth sets to ensure the top spot in Pool E.
Both teams will meet again in the 2020 AVC Women's Volleyball Olympic Qualification Tournament in January, with a single ticket to 2020 Tokyo Olympics up for grabs.
Japan have earned an automatic spot at Tokyo 2020 as the host nation, while China have booked their ticket after winning the intercontinental qualifiers in Ningbo earlier this month.