Ace Indian shuttler Saina Nehwal sailed into the Korea Open Super Series quarterfinals after notching up a 21-14 21-10 victory over Shao Chieh Cheng of Chinese Taipei in the second round of the women's singles in Seoul today.Commonwealth Games gold medal-winning pair of Jwala Gutta and Ashwini Ponnappa, however, were defeated by the formidable combo of top seed Xiaoli Wang and Yang Yu of China 10-21 17-21.