Four Thai players made it through to the quarter-finals of the women's singles on home territory at the Badminton World Federation (BWF) Thailand Masters Grand Prix Gold in Bangkok.
Number two seed Ratchanok Intanon, who is the best ranked player in the tournament after the withdrawal of India's Saina Nehwal, knocked out compatriot Supamart Mingchua in her second round tie at Nimibutr Stadium, 21-12, 21-13.
She will now face another Thai player, Nichaon Jindapon, in the last eight after her 21-16, 21-8 success over American Rong Schafer.
Porntip Buranaprasertsuk was another home favourite to make it through after the number seven seed saw off South Korea's Kim Hyo-min 21-15, 21-14.
That set up a quarter-final with another Korean, Sung Ji-hyun, while Busanan Ongbumrungpan is also still in contention for Thailand after making the quarter-finals with a 21-18, 21-14 success over Chen Xiaoxin of China.
She will face Dinar Dyah Ayustine of Indonesia in the quarters.
In the men's draw, South Korea's number one seed Lee Hyun-il reached the quarter-finals as he beat Thai hopeful Kantaphon Wangcharoen 21-11, 21-15 in round three.
That set up a clash with Hong Kong's fifth seed Wei Nan, who battled past Indonesia's Simon Santoso 17-21, 21-14, 21-14.
Korean second seed Son Wan-ho beat Malaysia's Zulfadli Zulkiffli 21-17, 21-14 to book a last eight appearance against fellow countryman Jeon Hyeok-jin, who beat Tan Chun Seang in three games, 21-17, 18-21, 21-9.
Home interest now solely rests with Tanongsak Saensomboonsuk, with the Thai making the quarters by knocking out South Korean Heo Kwang-hee 21-11, 16-21, 21-14.
He will now meet Hong Kong's number six seed Ng Ka Long, who defeated Indonesia's Firman Abdul Kholik 21-15, 21-14.
Another Hong Kong player, Hu Yun, is in the quarter finals after ending the hopes of Thailand's Boonsak Ponsana, 21-18, 21-12.
The number three seed will play India's Sameer Verma, who was too strong for his compatriot Anand Pawar, 21-4, 21-19.
The tournament continues in Bangkok tomorrow.