It was also curtains for the star Indian women’s pair of Jwala Gutta and Ashwini Ponnappa, who went down to the top seeded Chinese combination of Luo Ying and Luo Yu 11-21, 14-21 in 39 minutes.
Fourth seeded Sindhu was stunned 21-17, 21-19 by Thailand's Porntip Buranaprasertsuk in a match that lasted 38 minutes, while Prannoy, seeded seventh, lost 10-21, 15-21 to top seed Chen Long in 46 minutes.
Despite surging ahead thrice, Sindhu was unable to take the first game.
She first opened up a 4-1 lead, but the Thai girl drew abreast at 4. The Indian ace again led 7-4 and 13-10, but on both occasions was unable to maintain the momentum.
At 16-16, Porntip bagged three straight points to make it 19-16. Sindhu pulled a point back before the Thai wrapped the opening game 21-17.
In the second, Sindhu yet again took the lead and extended it to 11-8 at the break. But Porntip kept breathing down her neck and levelled scores at 13-13 before taking a two-point lead.
Thereafter, it was a closely-fought battle and the scores ran neck and neck till 19-all.
The Thai girl then held her nerve to reel off two significant points and seal the game and the match.
Earlier, Prannoy suffered his third defeat to twice World and All-England champions Long.
Prannoy, who had given the Chinese a scare in their last meeting at the Singapore Super Series earlier this month, failed to put up a fight.
In the opening game, Long broke away at 6-6 and never look back.
In the next, Prannoy opened up a 6-0 lead but the Chinese reduced it to 6-9 and then reeled off eight straight points to surge ahead and proceed to victory.
Image: P V Sindhu
Photograph: Robertus Pudyanto/Getty Images
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