Li Na of China celebrates after winning against Svetlana Kutznetsova of Russia at the Sydney International tennis tournament January 12, 2011. REUTERS

CANBERRA, January 12 (Xinhua)-- China's top tennis player, Li Na booked her place in the Sydney International semi-finals, after a grueling marathon win over Russian Svetlana Kuznetsova on Wednesday.

Li returned to the Sydney semi-finals for the first time since 2007, after out-lasting the two-time grand slam champion Kuznetsova with a 3-6 7-6 6-3 success coming after almost two-and- a-half hours.

The 11th ranked Li will now play Serbian qualifier Bojana Jovanovski in Thursday's semi-finals after she defeated Italian Flavia Pennetta 6-4 6-1.

Li Na of China returns the ball to Svetlana Kutznetsova of Russia at the Sydney International tennis tournament January 12, 2011. REUTERS

It was Li's fourth win against the former French and U.S. Open champion, Kuznetsova in their 11 meetings, and she was pleased to have got past Kuznetsova.

"It was a tough match because the conditions were hot today," Li told ABC Sports on Wednesday.

"It is always tough when we play each other. We have played many times.

"We didn't want to play a long match, but every time we play it 's long. We know each other pretty well and sometimes we practice together, so we know how each other plays on the court."