Saina, who is facing a race against time to qualify for her fourth Olympics, brushed aside Maria 21-10 21-19 in the second round to set up a last-eight clash with Thailand's third seed Busanan Ongbamrungphan, who has beaten the Indian twice in the last two encounters.
Sameer Verma also made it to the last eight with a hard-fought 21-14 16-21 21-15 win over Germany's Kai Schaefer. He will face either Thailand's Kunlavut Vitidsarn or Ireland's Nhat Nguyen in the men's singles quarterfinals.
However, former world no. 1 Kidambi Srikanth's wretched run continued as he went down 6-21 17-21 to fellow Indian Ajay Jayaram, dashing his hopes of qualifying for the Tokyo Games.
Srikanth, who had lost in the first round in Malaysia, Indonesia and Thailand, desperately needs to win a tournament or make it to the quarters and semifinals consistently to qualify for the Olympics.
N Sikki Reddy also endured a difficult day as she lost both the mixed doubles and women's doubles to bow out of the competition.
Sikki and her women's doubles pair of Ashwini Ponnappa, who is coming back from an injury, lost 18-21 14-21 to Bulgaria's Gabriela Stoeva and Stefani Stoeva, seeded third.
In the mixed doubles, Sikki and Pranaav Jerry Chopra went down fighting 16-21 21-17 11-21 to top seeded Malaysian pair of Goh Soon Huat and Lai Shevon Jemie.
Visit news.dtnext.in to explore our interactive epaper!
Download the DT Next app for more exciting features!
Click here for iOS
Click here for Android