Favourite Revati started in a whirlwind way by pocketing the first game 21-12, but Vaishnavi hit back hard and rallied splendidly to win the tie 12-21, 21-16, 21-19 in an hour-long battle of attrition at the Chembur Gymkhana.
Second seed Riya Pillai, third seed Mudra Dhainje and fourth seed Neha Pandit sailed into last four as they won their respective singles in straight games.
Fancied Abhishek S Kulkarni, of Pune, was taken the distance by Greater Mumbai's Viplav Kuwale before he prevailed 15-13, 13-15, 15-9 in 40 minutes to make the men's singles quarter-finals.
Results: Women's singles (Quarter-finals): Vaishnavi Bhale (NGP) bt (1) Revati Devasthale (PN) 12-21, 21-16, 21-19; (3) Mudra Dhainje (PN) bt Vaishnavi Iyer (MS) 21-11, 21-12; (4) Neha Pandit bt Shruti Mundada (PN) 21-13, 21-15; (2) Riya Pillai (MS) bt Vaidehi Choudhari 14-21, 21-16, 21-10.
Men's singles (Pre Quarter-finals): (1) Harsheel Dani (MS) bt Ajeet Kumbhar (PN) 15-8, 15-7; ; (4) Arjeet Bose (MS) bt Likhith Bangera (MS) 15-12, 15-7; (3) Nigel D'Sa (GM) bt Vinayak Dandawate (NS) 15-4, 15-2; Abhishek S Kulkarni (PN) bt Viplav Kuwale (GM) 15-13, 13-15, 1-9; Purushottam Awate (TH) bt Sonu Kumar (TH) 15-7, 15-5.
