Fifth seed Saina beat Indonesia's Fitriani Fitriani 21-16, 21-17, while Sindhu brushed aside Maria Febe Kusumastuti, another Indonesian, 21-10, 21-13.
World No. 8 Saina will meet the winner of the match between Indonesia's Lindaweni Fanetri and Thailand's Nitchaon Jindapol, while the 10th ranked Sindhu will take on eighth seed Tai Tzu Ying of Chinese Taipei, next.
However, it was a bad day in office for other Indians in the fray at the last tournament before the Olympic qualification deadline.
Kidambi Srikanth failed to cross the first round hurdle in the men's singles, shocked by unseeded Korean Lee Dong Keun.
The eighth seeded Indian was beaten 21-13, 12-21, 19-21 in 75 minutes.
Meanwhile, the Korean pair of Chang Ye Na and Lee So Hee beat Jwala Gutta and Ashwini Ponnappa 21-15, 21-11 in the women's doubles.
In the men's doubles, Manu Attri and B Sumeeth Reddy suffered a 15-21, 13-21 loss to the fifth seeded Japanese pair of Hiroyuki Endo and Kenichi Hayakawa and Pranaav Jerry Chopra-Akshay Dewalkar were beaten 19-21 17-21 by Hong Kong’s Or Chin Chung and Tang Chun Man.
Image: Saina Nehwal
Photograph: Warren Little/Getty Images for Falcon
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