PV Sindhu had it easy but Saina Nehwal was tested as the two Olympic medallists entered the women's singles quarterfinals of the USD 355,000 Singapore Open on Thursday.
The fourth-seeded Sindhu, a Rio Games silver medallist, took 39 minutes to get the better of world number 22 Mia Blichfeldt 21-13 21-19, her second straight win over the Danish shuttler, who had clinched the Spain Masters earlier this year.
World number 6 Sindhu will next face China's Cai Yanyan, a 2017 BWF World Junior Championships bronze medallist.
Sixth seed Saina, however, had to work hard in her bid to avenge a Malaysia Open first-round loss to Pornpawee Chochuwong before pulling off a thrilling 21-16 18-21 21-19 win over the Thai shuttler in the second round.
The London Olympic bronze medallist will next square off against second-seeded Japanese Nozomi Okuhara.
While Saina was plotting the downfall of Chochuwong, her husband and fellow shuttler Parupalli Kashyap was locked in a fierce battle with reigning Olympic champion, Chen Long of China.
Kashyap, a 2014 Commonwealth Games champion, stretched Chen to three games before narrowly losing 9-21 21-15 16-21 to the fourth-seeded Chinese, who had reached the finals at Malaysia Open last year.
Sameer Verma, however, continued his impressive run, beating China's Lu Guangzu 21-15 21-18 to set up a clash with either second-seeded Taipei player Chou Tien Chen or Denmark's Jan O Jorgensen.
Earlier in the day, Sindhu led throughout in the first game after opening up a 3-0 advantage but in the second game, she was locked in a tight battle with Mia till 8-8. The Indian was, in fact, trailing 11-15 at one stage.
However, Sindhu managed to claw back at 17-17 and then nosed ahead to seal the issue in her favour.
Sindhu had reached the semifinals of the India Open last month.