Johor Bahru: Indian shuttlers R.M.V. Gurusaidutt, P.C. Thulasi and Sourabh Varma entered the quarter-finals of their respective categories at the Malaysia Grand Prix Gold here Thursday.

While Thulasi overcame compatriot Tanvi Lad 21-2, 17-21, 21-18 in a one-hour and eight-minute marathon women's singles match, eighth-seeded Varma ousted Japanese ninth seed Kazumasa Sakai 21-15, 17-21, 21-19 in an equally tough men's singles match which lasted an hour and 11 minutes at the Stadium Perbandaran Pasir Gudang.