Two-time champion; Saina Nehwal and HS Prannoy have advanced to the singles semi-finals at the Swiss Open Grand Prix Gold Badminton tournament at Basel. Two-time champion Saina eked out a 13-21, 21-15, 21-14 win over Japan's Sayaka Sato, seeded seventh, in a 52-minute quarter-finals contest. The Olympic Bronze medallist will next take on her fierce rival Wang Yihan, seeded 3rd. Saina has a 4-9 record against the former World No. 1 but the top seeded Indian will take confidence from her three wins against the Chinese in 2015.In men's singles, 13th seed Prannoy took almost an hour to get across 16th seed Thailand's Tanongsak Saensomboonsuk, 21-18, 22-24, 21-9. The World No. 27 Indian will next face Tzu Wei Wang of Chinese Taipei.