Updated

By Ian Ransom

MELBOURNE (Reuters) - Li Na reached her goal of becoming China's first top 10 player quicker than expected after grinding down Venus Williams in three sets to join compatriot Zheng Jie in the semi-finals of the Australian Open Sunday.

The grueling 2-6 7-6 7-5 victory over the sixth-seeded American at Rod Laver Arena also ensured her and Zheng became the first Asian players to make the last four of the same grand slam.

The 27-year-old, who has battled injuries and Chinese officialdom for years to suddenly achieve her best results on tour, said she hoped the win over the seven-time grand slam winner Venus Williams was not her best.

"I don't want to say yes, because the tournament is not finished yet," a beaming Li told reporters after setting up a semi-final with Venus's younger sister Serena.

"So exciting. Maybe I take the beer tonight," she joked.

"Because my goal this year was top 10. But now it's only January so it's come quickly.

"I didn't think about that. I know the tournament is not finished. So (I'll) continue hopefully."

Li and Zheng's giant-killing run has ignited the draw at Melbourne Park and thrilled fans at home, where tennis, like all sports, was once denounced as bourgeois and banned under the rule of Mao Zedong.

"Right now you can see many media from China right here ... After the match I get 20 text messages from friends because they saw the match," said Li.

MORE FREEDOM

Along with Peng Shuai, Zheng and her grand slam-winning doubles partner Yan Zi, Li was permitted to manage her own schedule after previously having her arrangements decided by the state.

The watershed decision, which drew fire from more conservative officials in China, gave Li and her colleagues the right to keep more of their earnings.

Li, who has sometimes endured a fraught relationship with Chinese tennis officials, has clearly enjoyed the freedom.

Now working with Swedish coach Thomas Hogstedt, the hard-hitting Chinese broke through to the quarter-finals at the U.S. Open last year, her first last-eight appearance at a grand slam since her breakthrough at Wimbledon in 2006.

Long accused of being fragile under pressure and failing to fulfill her potential, she has now developed a tougher mental edge which she proved during the tense final set against Venus.

"Right now I am feeling good because I have my team coming with me," Li said. "And because I'm lazy (if) I didn't want to practice I just tell my team 'We take the day off'.

"Before, if I was with the national team, I say: 'Can I take a day off?' and maybe they say no to me."

(Editing by Alastair Himmer)