Koneru Humpy defeated lowly placed Zeinab Mamedjarova of Azerbaijan to stay in title race as Zhao Xue of China defeated overnight leader and compatriot Yifan Hao to emerge on top after the eighth round of the Is Bank Ataturk women's Grand Prix chess tournament in Istanbul on Tuesday.
Playing the white side of a Queen's gambit declined, Humpy (six points) had it easy against Zeinab to reach within a point of Zhao, whom she meets next.
If Humpy wins this game, she will be back in contention for the championship in this first Grand prix event which is also a part of the next world championship cycle.
Yifan slipped to second spot on 6.5 points and Humpy is third, half point adrift of the 15-year-old.
Elina Danielian of Armenia remained in fourth spot on 5.5 points after accounting for Betul Cemre Yildiz of Turkey.
The clash between former world champions - Bulgarian Antoaneta Stefanova and Maia Chiburdanidze -- ended in a draw after a tense struggle.
Martha Baquero Fierro of Ecuador suffered her fourth straight defeat in the event, bowing to Marie Sebag of France while Pia Cramling defeated Shen Yang of China.