India's ace shuttler Saina Nehwal has stormed into the semi-finals of the BWF World Super Series, winning two of her three round robin league matches. She defeated Japan's Sayaka Sato in a Group-B match 21-16, 21-13 in Liu Zhou in China yesterday.World No. 4 Saina had defeated Youn Joo Bae of Korea 21-14, 17-21, 21-14 in her opening fixture and was at the top of pool-B alongside third seeded Xin Wang of China.