Ace Indian shuttler P.V. Sindhu continued with her poor form when she got knocked out in the opening round of the ongoing China Open after a shock defeat to World No. 42 Pai Yu Po of Chinese Taipei on Tuesday. World No. 6, who made early exits in China, Korea and Denmark, lost 13-21, 21-18, 19-21 to Pai in a match that lasted for 74 minutes.