Star India shuttler PV Sindhu had to dig deep to beat Denmark’s Line Christophersen in the women’s singles opening round match, while HS Prannoy dished out a superlative display to shock world No. 6 Tien Chen Chou of Taiwan in men’s singles of the Malaysia Masters here on Wednesday.

Sindhu, seeded sixth, had to toil for an hour and two minutes to get the better of world No. 33 Christophersen 21-13, 17-21, 21-18, who the Indian had defeated four times earlier.

The Indian, a two-time Olympic medallist ranked 13th in the world, will next play Japan’s Aya Ohori.

World No. 9 Prannoy later held his nerves after going a game down to upset Chou, ranked sixth, 16-21, 21-14, 21-13 in his opening match to enter the pre-quarter finals.

Prannoy will next lock horns against Shi Feng Li of China, seeded eighth.

The other Indian man to enter the second round was Kidambi Srikanth, who defeated Toma Junior Popov of France 21-12, 21-16. He will next take on Thailand’s Kunlavut Vitidsarn.

However, it was curtains for qualifier Ashmita Chaliha, Aakarshi Kashyap and Malvika Bansod in the women’s singles competition as they crashed out in the opening round.

While Ashmita lost 17-21, 7-21 to fourth seed Yue Han of China, Aakarshi was shown the door by top seed Japanese Akane Yamaguchi 17-21, 12-21.

Malvika fell to second seed Zhi Yi Wang of China 11- 21, 13-21.