Serena Williams of the US speaks during a news conference at the Australian Open tennis tournament in Melbourne, January 12, 2013.

Melbourne - Serena Williams goes into the Australian Open a red-hot favourite in her quest for a sixth title with even world number one Victoria Azarenka admitting the American is the player to beat.

Williams gets her 13th Melbourne campaign underway Tuesday against Romania's Edina Gallovits-Hall, fresh from claiming her 47th career title in Brisbane and with a rare calendar-year Grand Slam in her sights.

But the formidable and newly focused American, 31, is doing her best to play down soaring expectations before the Grand Slam season gets underway at Melbourne Park on Monday.

“That's an incredible goal,” she said of the Grand Slam of winning the Australian Open, Roland Garros, Wimbledon and the US Open in the same year, a feat last achieved by Steffi Graf in 1988.

“It hasn't been done since the Eighties. I don't know if I can do it. Maybe someone else can. We'll see. But it's tough to say.”

Williams, who won Wimbledon, the US Open and Olympic gold last year, is also halfway to holding all the major titles at once for the second time, after first completing the non-calendar year “Serena Slam” in 2002-2003.

“I feel like I'm just in the moment right now. For this moment, I'm playing well. I really hope I can keep it up and continue to play well,” she added.

The 15-time Grand Slam winner sits behind defending champion Azarenka and Maria Sharapova in the current world rankings, but when it comes to the opening major of the season, she is peerless in the modern game.

She won in 2003, 2005, 2007, 2009 and 2010, and another Australian tournament victory would return her to world number one.

Azarenka, who withdrew from her Brisbane semi-final against Williams after failing to recover from a big toe infection, is happy for the American to be favourite, saying it takes the pressure off.

“Yeah, I think so,” she said when asked if Williams was her main obstacle, but she also said there were plenty of others looking to dethrone her.

“You know, everybody tries to beat the top players. Every time I go on the court, you feel the same way. Everybody wants to take your position, be the number one player in the world.”

Despite failing to complete her Brisbane warm-up event, the Belarusian said she felt relaxed going into the opening major of the year and fully recovered from her injury.

“I don't feel any pain when I play. I still have to tape it (the toe), but there is no problem,” she said.

Reigning French Open champion Sharapova, who was beaten by Azarenka in last year's final, is one of the players wanting to topple Azarenka but her preparations have been hampered by a collarbone injury.

However, the world number two said she could play her way into the tournament, starting against fellow blonde Russian Olga Puchkova, ranked 105.

“Yes, I might be a little bit rusty, but I'll work my way through it. I'm experienced enough to know the adjustments I have to make in those types of circumstances,” she said.

Former world number one Caroline Wozniacki could also be in contention, along with the in-form Agnieszka Radwanska, who has already won twice this year, and China's Li Na, the runner-up in 2011.

Li, 30, admitted that she was already feeling the pace after a frenetic start to the year.

“I've just had two days totally off. Now I'm feeling fresh again. The team was working so hard. Two days ago my body was feeling really, really tired,” she said.

Australian hopes rest with former US Open champion Samantha Stosur, who is yet to win a match this year. - Sapa-AFP