BEIJING (AFP) - World number one Zhang Yining will battle teammate Wang Nan for gold in an all-China women's singles table tennis showdown, after both won their semi-finals Friday.

Zhang defeated Singapore's Li Jia Wei 9-11, 11-8, 12-10, 11-8, 11-5 in their semi-final to move closer to clinching back-to-back gold medals in the singles after winning the title in Athens four years ago.

China, where table tennis is the national game, have never lost the women's singles crown since the sport was introduced at the 1988 Olympics.

Confident and composed, Zhang paid credit to the world number six, but said she knew she would win as long as she recovered from losing the first game.

"I think she (Li) fought really hard today," Zhang said.

"Her forehand is very aggressive. But I knew that so long as I got over the first game, I would be assured of a win," she said.

The Singaporean had been hoping for an upset after helping the city-state win its first medal in 48 years, with silver in the women's team competition.

But Li, who moved from Beijing to Singapore as a teenager, said she knew her chances were slim, having played Zhang 21 times before in major matches, and losing on every occasion.

"It's an achievement for me to finish in the top four while the other three are all Chinese players," the 27-year-old said.

Li and Zhang, 26, are both graduates of China's Beijing Shichahai Sports School which churns out elite athletes.

Li came out firing in the first game with some aggressive shots, racing ahead before Zhang saved four game points, only for the Singaporean to edge over the line 11-9.

But the world number one steadied in the second, taking an early lead and then holding off Li. The Singaporean went 6-3 up in the third but Zhang once again fought back to level 6-6 with a scorching cross-court forehand and then ease over the line.

In a tightly fought fourth game, featuring numerous fast and furious rallies, Zhang edged ahead when Li netted. Zhang, sensing victory, powered ahead in the last as Li wilted, the Chinese player winning when Li netted.

In the second-semi, veteran Wang downed world champion and teammate Guo Yue in a tightly fought contest, winning 3-11, 11-8, 4-11, 11-7, 11-3, 11-6.

Wang, 29, one of the most decorated paddlers in the history of the sport, is playing at her last Olympics.