Chen Xingtong booked her place in the World Table Tennis Macao final after a seven-game upset over world number one and Chinese team-mate Chen Meng.
The most in-form player on the women's singles circuit, Chen Meng suffered a shock defeat to the world number 13, despite being three games up.
With only one more to win, Chen Meng suffered a setback in an 11-10 fourth game defeat to Chen Xingtong, which stoked her comeback.
Chen Xingtong came through to win the match 10-11, 1-11, 7-11, 11-10, 11-9, 11-5, 11-7, setting up a final showdown with compatriot Sun Yingsha.
Sun faced fellow young Chinese player Wang Manyu in the other semi-final, also winning after seven games.
Wang was in control early in the match, going 3-1 up.
Despite a comeback from Sun, Wang held the match point in the sixth game, but lost it, requiring the match to go to game seven.
Wang had two more match points in the final game, but Sun stayed in contention, levelling the match at 10-10 before winning the next two points to ensure her place in the final, with the final score being 8-11, 11-7, 7-11, 2-11, 11-7, 11-10, 12-10.
In the men's semi-finals, Ma Long confirmed his spot in the final, following a 4-1 game win against his Chinese compatriot Lin Gaoyuan.
Despite some close games with Lin, Ma looked in control, winning 11-5, 11-10, 8-11, 11-7, 11-3.
Sweden's Mattias Falck saw his run come to a crushing end after defeating China's Xu Xin yesterday in the quarter-finals.
His opponent, Wang Chuqin, ensured all finalists in Macau would be Chinese after hammering Falck 11-3, 11-8, 11-8, 11-7.
Wang was superb in his first game, setting a precedent for the rest of the match where he won in straight games.
Chen Xingtong will face Sun Yingsha in the women's final and Ma Long will face Wang Chuqin in the men's final; both taking place tomorrow at the Tap Seac Multisport Complex in the Chinese territory of Macau.