Olympic champion Zhang Ning

World number one Xie Xingfang of Guangdong and reigning Olympic champion Zhang Ning both suffered early exits in the women's badminton on Wednesday in the quarterfinals of the 10th Chinese National Games yesterday.

Xie was upset 13-10, 11-3 by Hong Kong's Wang Chen and Zhang was eliminated by little known Zhu Lin of Shanghai 11-5, 6-11, 13-12.

Former Olympic champion Gong Zhichao from Hunan, who returned from retirement last December, was stopped by another rising star Jiang Yanjiao of the Chinese Army 6-11, 11-5.

Gong, who won the gold medal in the Sydney Olympics, lost to Jiang 2-1 and immediately announced to retire again.

Zhang attributed her loss to poor form, saying: "I have been not in form since I came here, and I'm physically weak," said Zhang, adding that Zhu played a excellent match.

The 21-year-old Zhu will next play former world number one Gong Ruina of Hunan, who ousted Lu Lan of Jiangsu 11-3, 11-5 in the day's another match.

Xie, also the newly-crowned world champion, only had herself to blame.

"I was in low spirits when we lost in the women's event, and I didn't talk about it with my coach," she said.

In the men's competition, all four top seeds advanced into the last eight after overcoming their rivals in the second round.

Top seed Lin Dan of the Chinese Army crushed Xie Xin from Fujian 15-8, 15-9 while second seed Chen Hong of Fujian overpowered Beijing's Du Pengyu 15-9, 15-0.

Bao Chunlai of Hunan, seeded No. 3, also eased through with a 15-2, 15-7 win over Jiangsu's rising star Li Yu.

"Bao is much more powerful than me, I still have a long way to go," said Li, who is considered as one of the medal hopefuls for the Beijing Olympics.

Bao will next face huge challenges from Guangxi's Chen Yu, who ousted Hong Kong's 24th-ranked Lin Guangyi.

Former world champion Xia Xuanze of Zhejiang, fourth-seeded in the event, eased past Xuan Chuan of Shanghai. He will meet Jiangsu's Chen Jin, who had to battle through Gong Weijie from Fujian in the second round 11-15, 15-12, 15-3.

In another match, Hu Yun from Hubei overcame Jiangsu's Qiu Yanbo 15-8, 12-15, 15-7 while Lu Yi, also from Chinese Army, beat Guangdong's Zhu Weilun 11-15, 15-10, 15-4.