Battle for number one as Kim, Serena lurk

Only a brave punter would bet against one of the 'Big Four' lifting the Australian Open men's title, but picking a winner from the women's draw is a hazardous task.

Novak Djokovic, Rafael Nadal and Roger Federer -- the top three in the men's rankings -- have an enviable haul of 30 grand slams between them in a golden period for the men's game. Just behind them lurks the hungry Andy Murray.

In sharp contrast, the top three female players have a combined total of just one slam and last year there were four different champions in tennis's blue riband events, as the women's game waits for its next big thing.

And acknowledged superstars Kim Clijsters and Serena Williams, both ranked outside the top 10 but sharing 17 major titles, are nursing recent injuries that could take the edge off their title challenges.

Belgium's Clijsters, currently ranked 12th, is defending champion at the year's opening grand slam, after beating Li Na in the 2011 Melbourne final, before the Chinese player went one step further at the French Open.

Second seed Petra Kvitova of the Czech Republic won on grass at Wimbledon and Australia's Samantha Stosur took the US Open title, upsetting home favourite Serena Williams in the September 11 final in New York.

The name missing from the 2011 list of winners is top seed Caroline Wozniacki, still yet to win her first grand slam, whose world number one ranking is under imminent threat from rising star Kvitova.

The two rivals have already clashed this year, with the Czech player winning in three sets at last week's mixed-teams Hopman Cup in Perth, which does not carry ranking points.

"It was a good match for us. It was good preparation," said Kvitova, the breakout player of 2011 with six titles including Wimbledon and the WTA Championships, plus Fed Cup glory with the Czech Republic.

Wozniacki, who reached the semi-finals in Melbourne last year, has been at pains to play down their rivalry, stressing her close friendship with the blonde Kvitova.

"Petra is a great girl. I like her a lot. She's one of my good friends," Wozniacki said. "I'm sure we'll play against each other and we'll both do well in the years to come," she added.

The Dane, buoyed by her relationship with golf superstar Rory McIlroy, will be anxious to seal her maiden grand slam and silence critics who say she cannot be considered the world's best player without winning a major.

Third seed Victoria Azarenka of Belarus has never been beyond the quarter-finals in Melbourne but reached the Wimbledon semi-finals last year.

By contrast, fourth seed Maria Sharapova has grand slam pedigree, with three major titles -- the last in Melbourne in 2008 -- but the Russian is again battling injury as she struggles to shake off a left ankle problem.

Stosur will have the crowd behind her as Australia's first women's grand slam champion in decades, but she has already admitted feeling the pressure after early exits in Brisbane and Sydney this month.

Li, last year's runner-up, is back in form after a disappointing second half of last season, and powerful Estonian Kaia Kanepi could be a dark horse after winning in Brisbane.

Venus Williams remains sidelined with autoimmune disease Sjogren's syndrome, and world number 10 Andrea Petkovic pulled out on Wednesday with a stress fracture in her back.

Clijsters, who has four grand slam titles and intends to retire this season, suffered a hip spasm during her Brisbane semi-final but said she did not believe her Australian Open participation would be jeopardised.

Also confident of being fit after an on-court scare is five-times winner Serena Williams, still the biggest draw in the women's game, who was forced to withdraw from the Brisbane event after painfully spraining her ankle.

The 13-time grand slam winner has won on three of her past four visits to Melbourne, and has not lost a match since falling to Jelena Jankovic in the 2008 quarter-finals.

While tennis is still locked in an enduring love affair with Williams, the 13th seed last week admitted she was ambivalent about the game and sports in general, saying she preferred "sitting down or shopping".

But comments since from the American star make it clear she has not lost her hunger and competitive edge.

The 30-year-old American, who looked lean and toned as she trained this week with her ankle strapped, tweeted: "Pain is only temporary but quitting lasts forever."