Phelps-powered US claw back in medal race

Beijing: China goes in search of more gold medals Friday in badminton, weightlifting, gymnastics and judo, but with the athletics programme kicking off its Olympic dominance could start to wane.

Heading into day seven, China has 22 gold medals, nine more than its nearest rival the United States who picked up three more in the pool on Friday.

But its weak point has traditionally been track and field with few serious medal chances, giving the Americans a chance to claw themselves back in the race to be named the world's top sporting nation.

The men's shot putt and women's 10,000m are decided with China virtually having no hope of a medal.

Xue Fei runs the distance race but has little chance of challenging the Ethiopian stranglehold.

But they have plenty of opportunity elsewhere.

Badminton, like table tennis, is a national sport in China with a feverish following and the home crowd will be expecting dynamic duo Du Jing and Yu Yang to beat South Korea's Lee Hyo-Jung and Lee Kyung-Won in the final.

China, who dominate the top seedings across the tournament, have won this event at the last three Olympics.

Badminton power couple Lin Dan and Xie Xingfang are also in action in the men's and women's singles semi-finals.

World champion Lin, the hot gold medal favourite, has an all-China blockbuster showdown against Chen Jun while his girlfriend Xie plays teammate Lu Lan, guaranteeing the host country at least one medal.

Defending women's champion Zhang Ning takes on Indonesia's Maria Kristin Yulianti in the other semi-final.

After shocking Venus Williams in the quarter's China top tennis player Li Na, the country's woman to reach the world's top 20, is due to play world No. 1 Jelena Jankovic for a place in the final.

China has won all three gymanstics golds so far but will be pushed in the women's all-round event with 16-year-old American sensation Shawn Johnson the athlete to beat.

Johnson won three golds at the world championships and has the potential to become the sport's next superstar with a similar performance on Friday.

In the Chinese camp, world champion Cheng Fei is the only gymnast with Olympic experience, finishing fourth in the vault at Athens, but is troubled by the burden of expectation.

"Sometimes I feel like it's hard to breathe or even cry under the pressure but once the competition begins I will think nothing and just strive for my best," she said.

China has won six weightlifting titles here so far and Cao Lei is tipped to add to the haul in the women's 75kg division, having won successive world championship titles.

Her biggest potential rival is Nadezda Evstyukhina of Russia.

Heavyweight jukoda Tong Wen is primed for another spectacular showdown with key rival Maki Tsukada.

Tong has claimed every world title in her category since 2003 and should have the mental edge.

Diving queen Guo Jingjing, who is retiring after Beijing, begins her campaign to claim her second gold of the Games when she competes in the 3m springboard preliminaries, with teammate Wu Minxia her main threat.

Meanwhile, China's women footballers play Japan for a place in the semi-finals.