Saina Nehwal fought off strong challenge from their opponents before winning their respective opening matches, but it was curtains for Lakshya Sen and B Sai Praneeth in Badminton Asia Championships on Wednesday. Two-time Olympic medallist Sindhu was made to toil hard by Chinese Taipei's Pai Yu Po as the fourth seeded Indian came back from a game down to win 18-21 27-25 21-9 in a marathon women's singles opening round match, which lasted for one hour and 17 minutes. London Olympics bronze medallist Saina, who has been on a comeback trail after recovering from some nagging injuries, also had to break her sweat to eke out a 21-15 17-21 21-13 win over Sim Yujin of South Korea.