Ace Indian shuttler Saina Nehwal turned in a superb display to stun world No 3 Xin Wang in the last Group B match of the BWF Super Series Finals in Liuzhou, China, on Friday.
The world No 4, who had already qualified for the semi-finals, won 21-17, 22-20 in 39 minutes.
She will meet Tine Baun of Denmark in Saturday's semi-finals.
Saina is now just a step away from becoming the first Indian singles player to enter the final in the Super Series Finals.
Jwala Gutta and V Diju had achieved the distinction in the mixed doubles at the 2009 edition of the tournament, where they lost to Christinna Pedersen and Joaquim Nielsen.
Trailing 4-8 in the first game, Saina reeled off seven straight points to go past Xin and wrest the lead at 16-12 after which she held her ground to pocket the game.
In the second game, the Indian ace opened a 9-2 lead and moved to 17-11, but the Chinese was not one to go down without a fight. She caught up at 19-19 and then registered another point to forge ahead 20-19.
However, Saina was unfazed and scored three straight points to shut the door on the Chinese.
With this victory, Saina improved her record against Xin, having beaten her twice this year, even though the Chinese defeated the Indian four times overall.
Despite the loss, Xin Wang also made it to the semi-finals, where she will take on compatriot world No 1 Yihan Wang in Saturday's other last four match.