In the men's singles, Parupalli Kashyap also booked a semifinal berth with a hard-fought victory over sixth seed Tien Chen Chou of Chinese Taipei.
Seventh seed Sindhu played a dominating game to assert her supremacy over two-time All England Champion with a 21-17 21-15 win in a 45-minute match to set up a semifinal clash with another fast emerging Chinese Sun Yu.
However, Olympic bronze medallist Saina had a tough time dealing with the world number three Yihan Wang as she slipped to a 17-21 2-21, her seventh defeat to a Chinese, in a 38-minute match.
Kashyap, meanwhile, took an hour and 14 minutes to tame Tien 21-15 21-23 21-18 -- his second win against the Taiwanese -- and would face world number 27 Houwei Tian of China in the semifinals.
World number 9 Sindhu showed once again why she is considered to be India's next big badminton sensation as she produced a beautifully controlled and carefully-paced game to keep Shixian at bay through out the quarterfinal match.