Saina ended with a lead of 11-3 at the change of end and beautifully controlled the game thereafter, showing her skill at the net, and smashing hard whenever the chance came.

'I was in trouble in the second game when she came back to draw level. She started playing long rallies and suddenly I was losing points. I was defending well though,' Saina said.

Jwala and Diju were the first Indian to take the courts Thursday evening. The duo had got a bye in the first round and had a walkover in the second against England's Nathan Robertson and Jenny Wallwork.

'I think the fact that we got two extra days helped us a bit. We trained hard and we are confident of doing well. It feels good to become the first pair to reach the quarterfinal,' said Jwala.

'We played them earlier in the Sudirman Cup four years back. We lost then but now we are a better combination. We put them under pressure. The crowd was cheering for us and that too helped us,' she added.

In other matches, defending champion Lin Dan of China raced to a 21-11, 21-11 victory against Dicky Palyama of the Netherlands.

The Chinese, who is aiming a hat-trick of world titles, set-up a quarterfinal clash with veteran Danish Peter Gade.

Third-seeded Gade showed his class and form as he beat 10th-seeded Chan Yan Kit of Hong Kong 21-11, 21-12 in another pre-quarterfinal encounter.

Top seed Lee Chong Wei of Malaysia beat Tien Ming Nguyen of Vietnam 21-13, 21-17 to reach the quarters. Chong Wei will meet sixth seeded Kuncoro, who beat Anand.

Women's world No.1 Zhou Mi of Hong Kong also advanced to the quarterfinals with a 21-11, 21-18 victory over Japanese Ai Goto.

Fifth-seeded Chinese Xie Xingfang faced a tough time against Thailand's Salakjit Ponsana but prevailed 21-16, 14-21, 21-9 to reach the last-eight. Seventh-seeded Chinese Lu Lan beat Wang Chen of Hong Kong 21-18, 21-14 for a place in the last eight.