Olympic silver medallist PV Sindhu sailed into the last four stage, while Nagpur's Vaishnavi Bhale and Ashmita Chaliha of Assam showed superb resilience to book their maiden semifinal spots on a dramatic day at the 83rd Senior National Badminton Championship on Thursday.
On a day when three pre-quarterfinals were postponed due to uneven court surface at the Assam Badminton Academy, Sindhu went about her business as usual, beating Riya Mookerjee 21-16 21-7 in 28 minutes to progress to the semifinals.
The top seed from Hyderabad, a former champion, had opened her campaign with a 21-11 21-13 win over Nagpur's Malvika Bansod in the morning.
Vaishnavi, who had won the All India ranking tournament 2015 and finished runners-up at 2016, dug deep to eke out a hard-fought 19-21 22-20 21-11 win over third seed Shriyanshi Pardeshi.
The maximum cheer was reserved for local sensation Ashmita, who kept her cool in two successive thrillers to set up a semifinal clash against Sindhu.
The 19-year-old left-handed sensation from Assam, who claimed her first two senior international titles at the Dubai International Challenge and Tata Open International Challenge last year, showed great rearguard action to secure a 16-21 21-17 21-19 win over Aakarshi Kashyap in the quarters.
The fourth seeded Assamese girl had earlier defeated Vaidehi Choudhari 21-13 15-21 21-12 in the pre-quarterfinals.
In men's singles, Lakshya Sen and Kaushal Dharmamer progressed to the last four with straight game wins over their respective opponents.
While Lakshya beat Aryamann Tandon 21-14 21-10, Harsheel Dani's superb run was cut short by Kaushal, who notched up a 21-11 21-19 to make his maiden semifinal spot at the tournament.
Earlier in the day, top seed Sameer Verma conceded a men's singles encounter against Aryamann Tandon midway at 21-16 1-8 after aggravating a achilles heel problem.
After that match, Saina took the court against Shruti Mundada in the pre-quarters but after having a look at the surface she made it clear that she won't risk playing on that "uneven" court with the All England Championship round the corner.
BAI secretary (events) Omar Rashid then postponed the three pre-quarterfinal matches, involving Saina, Parupalli Kashyap and B Sai Praneeth, to the evening session after consulting the players.
The organisers then prepared a fresh court on a thick wooden plank on the cement flooring at the TRP indoor stadium for Saina and Kashyap's pre-quarterfinals matches, while second seed Praneeth preferred to play at the adjacent court at the Assam Badminton Academy.
Earlier, Sourabh defeated Kartik Jindal 21-8 21-15, Lakshya brushed aside Ansal Yadav 21-11 21-8 and Harsheel stunned fourth seed and 2018 SaarLorLux Open champion Subhankar Dey 21-15 21-17.
In men's doubles, top seeds Arjun MR and Shlok Ramchandran defeated Rohan Kapoor and Saurabh Sharma 21-11 21-18 to enter the semifinals, while Pranaav Jerry Chopra and Chirag Shetty got the better off veteran pair of Rupesh Kumar and V Diju 21-8 18-21 22-20 to make it to the last four stage.
Arun George and Sanyam Shukla and Krishna Prasad G and Dhruv Kapila also advanced to the semifinals.
Like last year, the players ranked within top 50 in the BWF ranking and top shuttlers in the BAI ranking, filled up the top eight places, who were given direct entry in the singles pre-quarterfinals after a super draw was conducted on Wednesday night.