National Champion Prerna Bhambri scored the biggest upset of the event, knocking out top seed and world ranked 298 Ankita Raina, while eighth seed Nidhi Chilumula stunned third seed Rishika Sunkara to enter the semifinals of the ITF women's championships here.
Unseeded left-hander Sowjanya Bavisetti and second seeded Prathana Thombare also made it to the last four with contrasting wins.
In the quarter-finals, sixth seed Bhambri, ranked 593 currently, played attacking tennis in the second and the thrid set to topple top seeded Ankita 4-6,6-2,6-3 in a match that lasted for two hours and 15 minutes.
Ankita started the set with a 3-1 lead but Bhambri clawed her way winning three games in a row to go up 4-3. Raina Broke back in the 7th and the 9th games to win the first set 6-4.
In the second set, Prerna dominated the game with some attacking tennis breaking Raina twice to win the second set 6-2 and force the third set.
In the decider, both players held on till 3-3 when Prerna broke Ankita to go up 4-3. She then held on to her serve to take the score to 5-3.
In the 9th game, Bhambri led 0-40 , but Ankita showed signs of comeback making it duece, but lost two points again to falter and give Bhambri her first win over Raina in the last eight months.
"I played well today and felt in the zone," said Prerna after the match.
"I lost to a better player today," said Ankita.
In another upset match, eighth seeded Nidhi Chilumula scored a rather easy 6-3,6-3 win over third seeded and 515 ranked Rishika Sunkara in an hour and 45 minute tussle to make it to the last four stage.
Left handed Sowjanya Bavisetti of Hyderabad, who upset fourth seeded Emi Mutaguchi of Japan yesterday, continued her winning run scoring a 6-4, 7-5 win over Rutuja Bhosale in two hours.
Bhosale showed signs of comeback saving three match points at 4-5 and levelling scores to 5-5, but unforced errors saw her out of the tournament.
Second seeded Prarthana Thombare of Barshi went through a close three set tussle before overcoming a fighting seventh seeded Natash Palha winning 6-2,6-7(4),6-0 in 2 hours and 20 mins.
Palha swept the first set and led 6-5 before Thombare levelled scores to force a tiebreak. From then on the 405th ranked Thombare dominated the tiebreak and the third set to make it to the last four.
In the semfinals, Bhambri will take on Bavisetti, while Chilumula will take on Thombare.
(Quarter finals) Singles: Prerna Bhambri S.6 bt Ankita Raina S.1 4-6,6-2,6-3 Sowjanya Bavisetti bt Rutuja Bhosale (WC) 6-4,7-5 Nidhi Chilumula S.8 bt Rishika Sunkara S.3 6-3,6-3 Prarthana Thombare S.2 bt Natasha Palha S.7 6-2,6-7(4),6-0
Doubles (Quarter-finals): Sowjanya Bavisetti/ Sharmada Balu bt Emi Mutaguchi/ Chihiro Nunome 6-0,6-0
Shweta Rana/ Rishika Sunkara bt Akshara /Teertha Iska 6-4,6-1 Rutuja Bhosale/ Natasha Palha bt Saniya Madan/ Preethi Ujjaini 6-2,6-0
Ankita Raina/ Prarthana Thombare bt Anushka Bhargava/ Eetee Mehata 6-2,7-5.