BEIJING (AFP) - China again pushed its sporting boundaries Wednesday by claiming more Olympic firsts, winning its maiden yachting gold medal and booking a place in the women's hockey finals.

But the Yao Ming-led basketball team crashed out.

With 45 gold now in the bag, to the United States' 26, the race to be named the world's dominant sporting power is virtually sewn up.

The pickings for China were slim Wednesday, but Yin Jian made sure they were celebrating by taking the women's windsurfing title, adding to the silver she won in Athens in 2004.

It was a ground-breaking achievement in a sport usually dominated by Europeans, as Yin joined fencer Zhong Man and archer Zhang Juanjuan as Chinese athletes to win gold here in sports that China had never before excelled.

She saw off the threat of Italy's Alessandra Sensini, the 2000 champion in Sydney, and the four-time world champion.

"Ever since Athens I have been preparing for Beijing," she said.

"I can go proudly back to my hometown and tell my people that I have not let them down. Their dream came true and my goal was achieved."

China's sailing team captain Yao Xinpei said it would go down in the annals of history.

"It showed the improvement of the overall level of Chinese sailing," Yao said. "The medal race was really classic and it will be definitely recorded into the history of Chinese sailing."

In another breakthrough, the women's field hockey team entered an Olympic final for the first time with a 3-2 win over defending champions Germany.

Zhao Yudiao scored the winner 10 minutes before the end of a gripping semi-final where the home team delighted a boisterous crowd of 10,000 by twice fighting back from a losing position.

"We deserved to be in the final," China's delighted South Korean coach Kim Chang-back told AFP. "It was a dream of the girls to win an Olympic medal for the first time and now they have.

World champion Wu Jingyu added another gold by beating Thailand's unfancied Buttree Puedpong in the women's taekwondo -48kg final.

"It is a breakthrough for China in this weight category because no Chinese have won a gold in this before," said Wu.

"I have been waiting for this day for a long time."

And Zhang Wenxiu threw a personal best of 74.32m for bronze in the women's hammer to secure the hosts' a medal in the track and field.

It was a sadder story for twin sisters Jiang Tingting and Jiang Wenwen, who failed in their bid to win the synchronized swimming duet free routine gold.

They ended fourth behind Russian pair Anastasia Davydova and Anastasia Ermakova, who have now taken home gold at every international competition since 2002.

And there was also bitter disappointment for superstar center Yao as his dream of bringing China an Olympic medal collapsed in a 94-68 defeat to Lithuania in the quarter-finals.

"We've finished our journey for the Olympic Games, it's a shame. We were going to break the record for China (at the Olympics, to take) seventh or sixth place, but we didn't make it," a dejected Yao said.

After winning gold in the both the men's and women's team events, China's table tennis players are expected to follow suit in the singles.

Defending champion Zhang Yining crushed her hapless opponent Wednesday to open her campaign, with the world number one, who won gold in singles and doubles in Athens, demolishing Viktoria Pavlovich from Belarus 4-0.

The men start their title quest on Thursday.