On May 18, the 1/4 matches of the Thailand Open Badminton Championships were all over, and Japan and South Korea suffered Waterloo, and only one group of players advanced to the semifinals. Thailand emerged as the biggest winner, securing six places in the semi-finals.
- In men's singles, Kodai Naraoka was upset
Of the four matches in the men's singles, only one was played in three games, and the rest of the matches were all one-sided. No. 2 seed Kodai Naraoka did not perform well, losing 0-2 to Zhou Tiancheng and missing out on the semi-finals. Kunlavut had a weaker opponent and won easily 2-0, making it 21-5 in a single game. The strong duel between Ng Ka Long and Li Jiahao was also one-sided, and Ng Ka Long won easily 2-0. Li Zijia and Lu Guangzu played three games, and Li Zijia withstood the pressure and narrowly won 2-1 to advance. In the semifinals, Zhou Tiancheng vs Li Zijia, Kunlavut vs Ng Ka Long.
- In women's singles, China and Thailand swept the semifinals
The semi-finals of women's singles were won by China and Thailand respectively, China's overall advantage is still huge, and the overall strength of Thailand's women's singles has rebounded. Top seed Han Yue played comfortably, beating Indonesia's Koman Ayew 2-0 to advance. No. 2 seed Wang Zhiyi received Yang Jiamin's retirement gift and easily advanced. Thailand's Ge Thong defeated third seed Mariska 2-1, 22-20 in the second and third games. Li Meimisecond reversed China's Gao Fangjie 2-1 and advanced to the semifinals. In the semifinals, Han Yue vs Li Meisao, Wang Zhiyi vs Ge Tong.
- In Men's Doubles, Rankireddy/Shetty came out on top
Top seeds Rankireddy/Shetty were far ahead, easily beating Arif/Ye Ruiqing 2-0 to make it 21-7 in a single game. Chinese teenagers Chen Baiyang/Liu Yi fought hard in three games and narrowly defeated Zhenlong/Luo Shengsheng 2-1. South Korean veterans Kim Ki-jong/Kim Sa Rong put in a strong performance, easily beating Jiang Jianwei/Wu Xuanyi 2-0 to advance. The last spot was taken by Chinese Taipei's Lu Mingzhe/Tang Kaiwei, who reversed Chung Hongjian/Haikal 2-1 to advance to the semi-finals for the first time. In the semi-finals, Rankireddy/Shetty vs Lu Mingzhe/Tang Kaiwei, Liu Yi/Chen Boyang vs Kim Ki-jeong/Jin Sha Lang.
- In women's doubles, China was completely wiped out
The Chinese Women's Doubles was contested by two pairs, both of whom lost to top seeds Zongkong Pan/Rawinda. Zong Kong Pan/Rawinda defeated Li Yijing/Luo Xu Min 21-6, 22-20 to advance easily. India's Krasto/Ponnapa beat Korea's Lee Woo-rim/Shin Seung-chan 2-0 to advance. The other two semi-finals were won by Indonesia's Kusuma/Amalia and Japan's Suzu Iwanaga/Takaei Nakanishi, both of whom won comfortably 2-0. In the semi-finals, Sokong Pan/Rawinda vs Krasto/Ponnappa, Kusuma/Amalia vs Suzu Iwanaga/Takaei Nakanishi.
- Mixed doubles, 2 seats from Thailand
In the mixed doubles, Thailand became the big winner, winning both of the big matches between Thailand and Indonesia. Top seeds Dechapol/Sapsiri 2-0 Hidayatola/Pranata advanced to the tournament and Rutanapak/Jenicha 2-1 Kushayanto/Kusumavati. China's Guo Xinwa/Chen Fanghui defeated Thailand's Supak Supak/Puff Pastry Sara 2-1 to reach the semi-finals in their first match. Rivaldi/Mentari beat team-mates Dejan/Widjaja 2-0 to advance strongly. In the semi-finals, Dechapol/Sapsiri vs Rutanapak/Jenicha, Guo Xinwa/Chen Fanghui vs Rivaldi/Mentari.
At the end of the quarterfinals, Japan only had one pair of women's doubles left, and South Korea only had one pair of men's doubles left, almost all of which were wiped out. The Chinese team has two women's singles, one men's doubles, and one mixed doubles, with a total of four semi-final seats. Thailand emerged as the biggest winners, with a total of six semi-final spots.