Busanan Ongbamrungphan claimed the women's singles title at the US$400,000 BWF India Open in New Delhi on Sunday.
The second seed overcame fellow Thai Supanida Katethong 22-20, 19-21, 21-13 in one hour 16 minutes to win the her first title of the year at the World Tour Super 500 event.
Supanida had upset top seed Pusarla V Sindhu of India in the semi-finals on Saturday.
Busanan took home the US$30,000 (approx 1,002,000 baht) winner's cheque while Supanida received $15,200 (501,600 baht).
Earlier, Benyapa Aimsaard and Nuntakarn Aimsaard were crowned the women's doubles champions.
The Thai fourth seeded duo eased past third seeds Anastasiia Akchurina and Olga Morozova 21-13, 21-5 in just 34 minutes in yesterday's championship match.
The duo received $31,600 (1,055,440 baht) for their first World Tour 500 title.
Thai badminton boss Khunying Patama Leeswadtrakul congratulated the winners.
"It was a great start to the year for Thai shuttlers for winning two titles in India," said Patama.
"I would like to also congratulate Supanida for her huge victory over [Pusarla V] Sindhu, who is a former world champion and the Tokyo Olympics bronze medallist."
The men's singles title went to Lakshya Sen as the Indian upset world champion Loh Kean Yew of Singapore 24-22, 21-17.
In the mixed doubles final, Singapore's Terry Hee Yong Kai and Tan Wei Han defeated third seeds Chen Tang Jie and Peck Yen Wei 21-15, 21-18 to claim the gold medals.
Satwiksairaj Rankireddy and Chirag Shetty of India won the men's doubles title after beating Mohammad Ahsan and Hendra Setiawan of Indonesia 21-16, 26-24.