Indian Grandmaster Dronavalli Harika stunned world champion Ju Wenjun in the third round to grab a share of the top spot in the FIDE Women's Grand Prix chess tournament in Lausanne.
Harika, the world No.9, has two points after three rounds along with four others.
The Indian outlasted the 29-year old Chinese player, ranked No.3 in the world, in 54 moves with white pieces late on Wednesday.
The others on two points include Russians Alina Kashlinskaya and Alexandra Goryachkina, Anna Muzychuk of Ukraine and Georgia's Nana Dzagnidze.
Three of the six games on the day were decisive ones with Kashlinskaya and Muzychuk registering wins.
Kashlinskaya defeated former world champion Alexandra Kosteniuk while Anna Muzychuk got the better of Frrance's Marie Sebag in 38 moves.
The 29-year old Harika faces Dzagnidze in the fourth round later on Thursday.
The strong tournament featuring 12 players, including world champion Wenjun, is the third in the series of four Grand Prix from which two with the highest points would qualify for the next candidates event.
Results: Round 3: Dronavalli Harika (IND) 2 beat Ju Wenjun (CHN) 1; Anna Muzychuk (UKR) 2 beat Marie Sebag (FRA) 1; Alexandra Goryachkina (RUS) 2 drew Zhansaya Abdumalik (KAZ) 1; Alexandra Kosteniuk (RUS) 0.5 lost to Alina Kashlinskaya (RUS) 1; Antoneta Stefanova (BUL) 1.5 drew with Nana Dzagnidze (GEO) 2; Mariya Muzychuk (UKR) 1.5 drew with Pia Cramling (SWE) 1.5.