World No. 11 Sindhu prevailed over the fifth seed Han Li of China 21-17 19-21 21-16 in a match that lasted over an hour at the Tap Seac Multisport Pavilion. The second seed will next take on Busanan Ongbumrungpan of Thailand tomorrow.
Men's third seed Prannoy got the better of Indonesia's Sony Dwi Kuncoro 21-19 21-17 in 41 minutes. He faces Wong Wing Ki Vincent of Hong Kong for a place in the final.
In the second game, Sindhu once again surged ahead to a 11-6 lead but Han caught up with the Indian with a five-point burst.
The Indian then reeled off four points on the trot but the Chinese kept breathing down her neck, clawing back at 17-17. After a tough battle, it was Li who managed to get past Sindhu to roar back into contest.
Li carried the momentum in the decider early on as she moved to 6-3 but Sindhu soon wriggled her way out of the rut to lead 14-8.