The 27-year-old Belgian is favorite for the Australian Open but required all of her expertise at winning clutch points in a ding-dong battle with the big-hitting Russian at a windy Sydney Olympic Park.

The US Open champion clinched her place in the final in the third set tiebreak after a hard-fought two hours and 38 minutes, maintaining her record of not having lost a semifinal or final since coming out of retirement in 2009.

In Friday's final, Clijsters will meet China's Li Na, who continues to suggest she might match or even better last year's breakthrough at Melbourne Park.

The 28-year-old, who made it to the semi-finals at the year's first grand slam in 2010, came back from a break down in the first set to beat Serbian teenager Bojana Jovanovski 7-6, 6-3.

Former top 10 player Gilles Simon continued his battle back from a serious knee injury to reach the last four in the men's tournament with a 6-4 6-3 win over Ukrainian Alexandr Dolgopolov on a windy day at the Sydney Olympic Park.

The French baseline hustler, who was ranked as high as sixth in the world at the start of 2009 after beating Roger Federer, Rafa Nadal and Novak Djokovic in 2008, said his mobility was improving.

Serbian Viktor Troicki later beat Frenchman Richard Gasquet 6-4, 6-4 to set up a last four meeting with German Florian Mayer, who surged past Italian Potito Starace 6-4, 6-1.

In Auckland, former world No. 3 David Nalbandian beat ailing defending champion John Isner 6-4, 7-6 (3) on Thursday to reach the semifinals of the Heineken Open.

Nalbandian, the No. 6 seed in Auckland and the 27th-seed for next week's Australian Open, beat the third-seeded American who appeared to be troubled by an arm injury on Thursday.

Isner needed medical treatment to an injury to his upper arm or shoulder but still delivered eight aces and put 78 percent of first serves in play before the steadier Nalbandian ended his title defense.

The tournament's top two seeds, Spaniard's David Ferrer and Nicolas Almagro, also won through to the semifinals in three-set matches.

Nalbandian will play Almagro in the semifinals while Ferrer will take on unseeded Colombian Santiago Giraldo who beat the No.7 seed Thomaz Bellucci of Brazil 6-2, 6-4.

Top-seed Ferrer beat No. 8 seed Philipp Kohlschreiber of Germany 6-3, 6-7 (4), 6-3 in a marathon match between former champions. Ferrer won the Auckland title in 2007 and Kohlschreiber in 2008.

Almagro needed three sets to end the giant-killing run of French qualifier Adrian Mannarino, 7-6 (3), 6-7 (1), 6-2.

The 22-year-old Mannarino, ranked 80, beat No. 5 seed Juan Monaco of Argentina in the first round and eliminated last year's runner-up, his compatriot Arnaud Clement in the second round.

He also pressed the No. 14-ranked Almagro for more than 2-1/2 hours before succumbing.

In Melbourne, persistent rain confined a raft of Australian Open contenders to the clubhouse at the invitational Kooyong Classic on Thursday, washing out the second day and leaving organizers with headaches to cobble a working schedule.

Rain had already washed out a first-round match between France's Jo-Wilfried Tsonga and Jurgen Melzer of Austria on Wednesday evening and continued to pour down on Thursday.

With the four-day schedule already cramped, Tsonga and Melzer have agreed to play a one-set decider on Friday to produce a semifinalist at the Australian Open warm-up tournament before the other scheduled matches.

The rain also scuppered Andy Murray's plans of playing an exhibition match with Croatia's Marin Cilic at the tournament, as the world number five Briton seeks a final tune-up before Melbourne Park which starts Monday.

Stubs said Murray would be unlikely to be able to get a rescheduled match with Cilic, who he beat in a pulsating four-set semifinal at the Australian Open last year.