The 11th seed, Sindhu, who clinched the bronze medal in 2013 and 2014 editions, had to dig deep into her reservoir of talent to outwit Denmark's Line Kjaersfeldt 11-21 21-17 21-16 in a 50-minute match.
The World No. 13 Indian had spent most of the time this season nursing an injury and had been struggling for form. Sindhu, who got a bye in the first round, will next take on Olympic champion and former World No.1 LI Xuerui of China in the prequarterfinals.
In the women's singles match, Sindhu was caught offguard by Line, ranked 35th in the world, as she didn't give the Indian any chance in the first game and held on to an early 6-1 lead to earn the bragging rights.
The Indian got her bearings in the second game as she opened up a 5-2 lead but Line clawed back at 7-7. Sindhu, however, once again drifted away and managed to held on to her lead even though Line kept breathing down her neck.
In men's singles, Srikanth had no problems as he quickly broke off at 4-4 and 6-6 in the first and second game respectively and held on to his fort to eventually come up trumps.