Saina Nehwal and the mixed doubles pair of Jwala Gutta and V Diju were the first Indians to enter the quarter-finals in the World Badminton Championships, even though it was curtains for Chetan Anand in the men's singles, in Hyderabad, on Thursday.
Saina scripted a scintillating comeback after losing the opening game against tenth seed Petya Nedelcheva of Bulgaria. She won 18-21, 21-18, 21-10 in a 57-minute encounter.
In Friday's quarter-finals, the sixth seeded Indian will take on second seed Chinese Lin Wang, who she beat in the Indonesian Super Series final recently.
In the mixed doubles, Jwala and Diju, who got a bye in the first round followed by a walkover in the second, opened their campaign in rollicking style, outclassing the 12th seed polish duo of Robert Mateusiak and Nadiezda Kostiuczyk 21-11, 22-20 in a 31-minute clash.
However, World No 15 Anand lost 16-21, 16-21 to sixth seed Sony Dwi Kuncoro of Indonesia, thereby putting an end to India's challenge in the men's singles.
Among others in the fray, fifth seed Lin Dan swept aside Dutch Dicky Palyama 21-11, 21-11 in 31 minutes to set up a quarter-final clash with third seed Peter Hoeg Gade of Denmark. The veteran Dane beat 10th seed Yan Kit Chan of Hong Kong.
World No 1 Malaysian Chong Wei Lee defeated 14th seeded Tien Minh Nguyen of Vietnam 21-13, 21-17 in a 33-minute battle, while world No 4 Indonesian Taufik Hidayat outplayed ninth seed Yu Hsing Hsieh of Chinese Taipei, winning 21-15, 21-19.
In a big upset in the women's singles, 11th seed Juliane Schenk of Germany beat fourth seeded Chinese Yihan Wang 21-18, 21-15 in 39 minutes.
In other matches of the women singles, top seed Mi Zhou of Hong Kong beat Japanese Ai Goto 21-11, 21-18, fifth seed Chinese Xingfang Xie defeated Thai Salakjit Ponsana 21-16, 14-21, 21-9 and seventh seed Chinese Lan Lu beat ninth seed Chen Wang of Hong Kong 21-18, 21-14. Eighth seed Hongyan Pi of France also notched an easy win over 15th seed Indonesian Maria Kristin Yulianti 21-13, 21-14.
Second seed Lin Wang of China also struggled her way into the last eight round, beating 12th seed Korean Hye Youn Hwang 21-10, 23-21, while third seed Dane Tine Rasmussen outlasted 13th seed Pui Yin Yip of Hong Kong 21-13, 11-21, 21-15 in 52 minutes.
Playing in front of her home crowd, Saina started off well and even secured a four-point lead at 14-18 at one stage but failed to maintain the momentum towards the end and gave away the game to her opponent.
However, the World No 6 bounced back in style in the second game and raced away to a 6-0 lead and extended it to 18-10. The Bulgarian then scripted a brilliant fight back to draw parity at 18-18 but Saina kept her pocket the game and level the scores.
In the third game, the 20-year-old Hyderabadi engaged the Bulgarian in long rallies and then mixed it up with soft drops.
She opened up a 7-2 lead and extended it to 11-3 and from thereon ensured that there was no further hiccups even though Petya tried to make a comeback.
"The third game was really well but I am not happy with the first game as I made too many mistakes. I was involving in more long rallies as my dribbles were not well and she was smashing the shuttle well but my defense was good," Saina said after the match.
"In the second game, it was really tough as I was leading 18-11 but she bounced back but I think I kept my cool and it paid off," she said.
Asked if she felt fatigued, Saina said, "I was not feeling tired and I think that is a good sign especially when I am playing a tougher opponent in the next round.
"It will be a very tough match against Wang but I will give my 100 per cent."
While Saina had to carve out a hard-fought win, Jwala-Diju broke little sweat in getting past the Robert-Nadiezda pair.
The world No 8 pair did not allow their Polish rivals to recover from their initial onslaught and pocketed the first game without any hassle.
The Polish combo came back strongly in the next game and took a three point lead at 13-16 but the Indian duo pocketed three straight points to draw parity and then moved neck and neck till 18-18.
The Polish duo soon grabbed two points to reach 20-18 but Jwala-Diju pair saved two match points to first claw back and then pocketed another two pointer to seal the match at 22-20.
"I think this two extra days helped us. We had played against them four years ago in the Sudirman cup. I was unwell and we lost that match but today we were confident. They were under pressure with the crowd cheering for us," Jwala said.
The world No 8 Indian pair will face defending champions and second seed Nova Widianto and Liliyana Natsir of Indonesia in the quarter-finals on Friday.
"We have played against them and we won, so we have a bonus I feel," Diju said.