SYDNEY - Agnieszka Radwanska needed eight match points to finish off Li Na on Thursday but confirmed her fine pre-Australian Open form by maintaining her perfect start to the year and reaching the final of the Sydney International.

Agnieska Radwanska of Poland hits a return to Li Na of China during their women's singles semifinal match at the Sydney International tennis tournament, Jan 10, 2013. [Photo/Agencies]

The Polish top seed was well worth the 6-3 6-4 win over her Chinese opponent and will face Dominika Cibulkova in Friday's final after the Slovakian stunned German second seed Angelique Kerber 6-2 4-6 6-3.

"I think I was really playing good tennis the last couple of days," said Radwanska, who also won the Auckland Classic last week and has started the year with eight straight wins. "I hope I can continue playing at this level."

David Ferrer has played six fewer matches than Radwanska this year but really hit his stride on Thursday when he swept aside Lukas Lacko 6-2 6-1 to remain on course for a fourth title at the Auckland Open.

The Spaniard, who like Radwanska will be seeded fourth at Melbourne Park next week, needed just 54 minutes to beat his Slovak opponent and set up a semifinal against France's Gael Monfils, who later beat Tommy Haas 3-6 7-5 6-3.

The fifth seed in the men's draw for the year's first Grand Slam, Tomas Berdych, had a less enjoyable day down at Kooyong where he was humbled 6-3 6-2 by Australia's resurgent former world number one Lleyton Hewitt.

Hewitt, now 31 and ranked 82nd in the world, beat Milos Raonic in his first round robin match on Wednesday and his 88-minute victory over Czech Berdych puts him into the final of the exhibition event.

There he will meet either Argentina's world number seven Juan Martin Del Potro or Cypriot Marcos Baghdatis, who face off at the Kooyong Classic on Friday.

"I'm just thrilled to be able to perform like this against quality players and on back-to-back days," Hewitt told reporters.

"I've had five tough sets in two days and that will hold me in good stead for next week."

Li Na of China hits a return to Agnieska Radwanska of Poland during their women's singles semifinal match at the Sydney International tennis tournament in Sydney, Jan 10, 2013. [Photo/Agencies]