The 18-year-old rising star Kunlavut stunned world No.11 Sai Praneeth B, the fourth seed from India, 21-11, 21-17 in the second round of the BWF World Tour Super 300 event.
World No.41 Kunlavut will take on another home hope Sourabh Verma, ranked 36th, for a place in the semi-finals.
Kunlavut has won four BWF International Challenge tournaments this year but today will be his only second quarter-final appearance at a World Tour level event.
He also reached the quarter-finals at the Macau Open, a World Tour Super 300 tournament, earlier this month.
Kunlavut is the second player to achieve the historic treble, joining compatriot Ratchanok Intanon in the elite list, who won three girls' singles world titles in a row from 2009-2011.
In the women's singles event, Phittayaporn Chaiwan defeated Porntip Buranaprasetsuk 21-8, 21-10 to advance. She will play China's Wang Zhiyi in today's quarters.
Saranchana Chaikittiwat and Supissara Paewsampran failed to progress, losing to seventh seeds Baek Ha-Na and Jung Kyung-Eun of South Korea 9-21, 13-21 in the women's doubles competition.