Fourth seeded Benyapa and Nuntakarn Aimsaard were crowned the women's doubles champion at the BWF India Open in New Delhi on Sunday.
Benyapa and Nuntakarn took only 34 minutes to beat third seeds Anastasilia Akchurina and Olga Morozova of Russia 21-13, 21-5 for their first Super 500 win and first world series.
The Thai pair earned US$31,600 (1 million baht) from the victory.
"We tried to keep ourselves calm throughout the match although we were excited about our first Super 500 final," Nuntakarn said after the match.
"I am glad we finally made it," added her younger sister Benyapa.
Thai players are guaranteed the women's singles crown in the same competition as the final - to be played later on Sunday - will be between second seed Busanan Ongbamrungphan and her compatriot Supanida Katethong.