Saina Nehwal, PV Sindhu Enter Quarterfinals of India Open

Defending champion Saina Nehwal and two-time World Championship bronze medallist PV Sindhu advanced to the quarterfinals but it turned out to be a dismal day for star shuttlers Lin Dan and Lee Chong Wei, who crashed out of the India Open Super Series. (Read More in Badminton)

Sindhu was a little circumspect during the match and committed a few unforced errors before surpassing Thailand's Busanan Ongbumrungphan 17-21, 21-19, 21-16 in a women's singles match that lasted an hour and 16 minutes.

She will next take on Korea's Bae Yeon Ju, who beat Japan's Yui Hashimoto 21-16, 21-10 in another match.

Later in the day, Saina saw off Nitchaon Jindapol of Thailand 21-19, 21-14 to set up a clash with Korean fifth seed Sung Ji Hyun.

However, the highlight of the day was the stunning losses of two-time silver medallist Lee Chong Wei and five-time World Championship Lin Dan, considered to be the biggest contenders for the Rio Games gold medal.

While Korea's Son Wan Ho stunned the six-time All England champion Lin Dan of China, seeded fourth, 21-13, 22-20, former World no. 1 Lee, top seed, suffered a 19-21, 19-21 loss to Hong Kong's Wei Nan, ranked World No. 14. Two more top 10 players bite the dust in men's singles at the Siri Fort Sports Complex.

While Xue Song saw off Denmark Jan O Jorgensen, seeded third 21-18, 15-21, 21-14 to emerge as the only surviving Chinese in men's singles, Germany's Marc Zwiebler stunned Chinese seventh seed Tian Houwei, who had reached the finals of the All England Championship, 18-21, 21-19, 23-21 in a thrilling contest in the men's singles.

Among other Indians, Rituparna Das sank without trace against fourth seed Ratchanok Intanon of Thailand 9-21, 4-21 in just 21 minutes in a women's singles clash.

In women's doubles, Mohita Sahdev and Sanjana Santosh defeated compatriot Ch Poornima and Rachita Sahdev 21-16 21-7.

They will meet Japanese combo of Naoko Fukuman and Kurumi Yonao.

Manu Attri and B Sumeeth Reddy suffered a 19-21, 12-21 loss to Chinese Taipei's Chen Hung Ling and Chi-Lin Wang, while Jishnu Sanyal and Shivam Sharma lost 17-21, 15-21 to Chinese Taipei's Lee Sheng Mu and Tsai Chia Hsin in another men's doubles match.

Indian pair of Gauri Asaji and Karishma Wadkar also suffered an embarrasing 5-21, 7-21 loss to top seeds Nitya Krishinda Maheswari and Greysia Polii of Indonesia in women's doubles, while Manu and Ashwini Ponnappa also lost 10-21, 17-21 to Chinese pair of Zhang Wen and Jia Yifan.

After losing the opening match, Sindhu changed gears and nosed ahead to a slender 11-9 lead in the second game. From 14-11, the Thai girl started catching up with Sindhu after the Indian failed to connect a few strokes. One such miscued shot at the net took Busanan to 14-14 and she soon grabbed a couple more to have a 16-14 advantage.

The Indian came up with a couple of smashes to draw parity at 17-17. With Busanan finding the net and then hitting wide meant Sindhu had a two-point lead at 20-18. The Indian hit one at the net but roared back into contest when her rival found the net.

In the decider, Sindhu lagged 0-4 early on but she managed to grab six consecutive points to march ahead to a 6-4 lead. Sindhu stretched the lead to 10-7 but she blew it with Busanan entering the break with a 11-10 lead.

After the interval, Sindhu started dominating the proceedings and grabbed an 18-15 lead before another wide shot broke the rhythm. A fierce rally then ended with an unforced error from the Thai player. Sindhu then grabbed the next two points when Busanan failed to connect a couple of strokes at the forecourt.

"It was a close match and it is good to have a tough opponent early in the tournament because it helps you to adjust with the conditions. I was playing her after a long time and I made lot of unforced errors. I was leading and then giving away points. Even some line judgements were not right. I am happy to win and hope to play better tomorrow," Sindhu told reporters.

Olympic bronze medalist Saina, who took the court in the later in the day, found the going tough initially against a spirited Jindapol as the duo engaged into a battle of attrition. Both moved neck and neck before a misjudged shuttle from Saina gave a slender 11-10 lead to the Thai girl at the break in the opening game.

Jindapon continued to extend her lead before Saina clawed back at 15-15 with a powerful smash which her rival ended up buring at the net. the duo moved neck and neck till 19-19 before Saina grabbed the advantage with a soft return which Jindapon failed to negotiate. She then pocketed the game with a lightening smash.

In the second game, Saina had found his bearing as she entered the break at 11-8 and never looked back. She continued her domination even as Jindapol crumbled.

Among others, Second seed Kento Momota of Japan defeated Hong Kong's NG Ka Long Angus21-16 21-11, while Denmark's Hans-Kristian Vittinghus notched up an upset win over Chinese Taipei's Chou Tien Chen, seeded sixth, 21-12, 21-12 in another men's singles match.

In women's singles, Sixth seeded Chinese Wang Shixian saw off Japan's Sayaka Sato 19-21, 21-11, 21-14, while former world No. 1 Chinese Li Xuerui, seeded 3rd, went past a fighting Porntip Buranaprasertsuk of Thailand 17-21, 21-13, 23-21 in a 54-minute clash.