Continuing their brilliant performance, ace Indian singles shuttlers Saina Nehwal and P.V. Sindhu entered the semi-finals to assure two historic medals of the Asian Games here on Sunday.Olympic silver medallist Sindhu edged past Thailand's Nitchaon Jindapol 21-11, 16-21, 21-14 while Saina defeated Ratchanok Inthanon of Thailand 21-18, 21-16.This is the first time Indian women singles shuttlers are assured of a medal in Asian Games. And India will have the first singles medals in badminton after the 1982 Asiad when Syed Modi won the bronze.In her match which lasted 42 minutes, Saina trailed in the initial stages of the first game but then bounced back to win.The second game saw a much improved performance from Saina who dominated the game with some swift court movements and powerful shots.Sindhu took around an hour to overcome her Thai opponent.Sindhu bagged the first match with ease but in the second the Indian shuttler struggled, resulting in her defeat.In the decider, Sindhu found her groove with some attacking shots and clinched the marathon match to assure India at least a bronze medal.