Defending champion Lee Chong Wei from Malaysia eased into the men's singles quarterfinals at All England Badminton on Thursday before Olympic champion Lin Dan grabbed his last eight berth also in straight games.

The world No. 1 Lee showed no mercy in the first match on Thursday as his jump smashes made the Chinese ace Bao Chunlai helpless.

After winning the match 21-16, 21-16, Lee updated his head-to-head against Bao to 11-5. He will meet the eighth seed Boonsak Ponsana from Thailand, who knocked out South Korean qualifier Lee Hun Il 22-20, 21-12.

Later, four-time All England champion Lin Dan beat Indonesian Dionysius Hayom Rumbaka to set up a clash with the seventh seed Nguyen Tien Minh.

Lin, who played Rumbaka for the first time, met little challenge all through the match, taking victory in 21-11, 21-17.

"I know he is the No. 4 player in Indonesia and he once beat Chen Jin. Therefore, I take the match against him seriously," Lin commented on Rumbaka.

World champion Chen Jin suffered an unexpected blow as he was knocked out by German Marc Zwiebler in straight games.

The sixth seed Chen admitted he was not in form and made too many mistakes in attack while Zwiebler regarded the win as the best one in his career as he was usually "kicked ass" by the Chinese players .

Besides, Danish veteran Peter Gade defeated Japanese talent Kenichi Tago 21-9, 22-20.

The 34-year-old European top player was 16-20 down in the second game, but was calm enough to collect six points in a row to wrap it up.

"Tago played much better in the second. But I managed to hold him off and made him see that you can hit some fantastic shots but I' m still going to win," said the fourth seed Gade who will meet Chinese hopeful Chen Long in the quarterfinals as the fifth seed enjoyed a walkover in the last 16.

In the women's singles, world No. 1 Wang Shixian and the third seed Wang Xin both reached the quarterfinals without sweat as their opponents as well as teammates quitted due to injuries.

Liu Xin was out for toe infection while Li Xuerui gave up due to the pain on her lower back.

Former world champion Lu Lan and the sixth seed Jiang Yanjiao played the Chinese derby with Jiang winning 21-11, 15-21 and 21-17.

Jiang will fight for a semifinal berth with Wang Xin.