Defending champion Kunlavut Vitidsarn began his Thailand Open campaign on Wednesday by swatting aside Yudai Okimoto 21-16, 21-12 to start his bid to become the first men's singles player since Joko Suprianto in 1994 to win three titles.
The world No.2 delighted fans at the Nimibutr Stadium with a dominant display which left the 35th-ranked Japanese Okimoto little room to breathe in the first-ever meeting between the two players.
Kunlavut, who won the tournament in 2023 and 2025, will face the winner of the match between Lee Chia-hao and Chi Yu-jen, both from Taiwan, in the last 16.
Earlier, rising star Panitchaphon Teeraratsakul suffered an early exit, losing to another upcoming player, Moh Zaki Ubaidillah of Indonesia, 10-21, 18-21.
Pitchamon Opatniputh pulled off a big upset in the women's singles event after she knocked out eighth seed Supanida Katethong, the 2024 champion, 21-15, 22-20. The 19-year-old former world junior champion will face Devika Sihag of India next.
Other Thai women's singles stars all moved safely into the last 16.
Busanan Ongbamrungphan defeated Yeo Jia Min of Singapore 21-16, 21-6; fourth seed Pornpawee Chochuwong edged Unnati Hooda 11-21, 21-17, 21-16 and Yataweemin Ketklieng eliminated Goh Jin Wei of Malaysia 13-21, 21-19, 21-16.
Awaiting Busanan in the last 16 is Japanese top seed Akane Yamaguchi, who defeated Han Qian Xi of China 21-17, 21-15, while Pornpawee and Yataweemin will face off in an all-Thai last-16 clash.
In the mixed doubles event, Ruttanapak Oupthong and Jhenicha Sudjaipraparat battled past Alexander Dunn and Julie MacPherson of Scotland 17-21, 21-19, 21-13 to book their last-16 berth.
In other notable results, men's top seed Shi Yuqi of China cruised past Anthony Ginting of Indonesia 21-12, 21-17; third seed Anders Antonsen also advanced with a 21-7, 21-17 win over Jason Gunawan of Hong Kong; sixth seed Kodai Naraoka also came through his opening match after he beat Ayush Shetty of India 21-13, 17-21, 21-4.
Eighth seed Loh Kean Yew of Singapore became the first men's seeded player to exit the tournament after he lost to Srikanth Kidambi of India 14-21, 15-21.
Meanwhile women's second seed Chen Yufei of China came through her first round match in a battling display, overcoming India's Anmol Kharb 19-21, 21-13, 21-18.
Chen will play another Indian, Malvika Bansod, in the last-16 round.
