Second seed Saina got the better of her Thai opponent 21-16 21-18 in 35 minutes.
Sindhu's defeat though prevented an all-Indian second round clash as both the Indian girls are in the bottom half.
Sindhu lost her gruelling first round 21-16 15-21 14-21 to Chinese Taipei's Ya Ching Hsu in 49 minutes. Saina will now take on Ching Hsu for a place in the women's singles quarterfinals.
World number 14 Kashyap next faces fifth seed Korean Wan Ho Son.
Later in the day, Kidambi Srikanth will open his campaign against Danish Hans-Kristian Vittin, ranked 15th in the world.
In the women's doubles the Indian pair of Jwala Gutta and Ashwini Ponnappa will open their campaign against Taipei's team of Ya Ching Hsu and Yu Po Pai.