The return of Justine Henin [Images] has added an intriguing twist to an Australian Open women's tournament overflowing with talent and mystery.

The world number one won the title in 2004 but lost the 2006 final to Amelie Mauresmo when she quit because she was feeling sick.

She was criticised for not playing on and allowing Mauresmo to experience the full exhilarating feeling of winning her first grand slam title but remains adamant there was nothing she could have done.

"I have no regrets," she said. "I was feeling so bad. I wasn't healthy enough to play that match.

"I wanted this title so much so it was tough but I don't have anything to prove to anyone."

Now 25 and at the top of her game, Henin would love to add a second Australian Open to her collection of grand slam titles. She missed last year's tournament during the personal upheaval of separating from her husband.

But she went on to win the French and US. Open titles and has made the final in six of the last seven grand slam tournaments she has entered but believes this year's Australian Open is wide open.

"As the number one player in the world I can understand that everyone sees me as the favourite but I can tell you anything can happen.

"You need to be strong mentally, physically and you need a little bit of luck also. It's long story, I can tell you, so you must go step by step."

Unlike the men's tournament, where world number one Roger Federer [Images] is an overwhelming favourite, women's tennis is more competitive than ever.

There are at least half a dozen genuine hopefuls for the first major of 2008 and the rankings offer little guidance to finding the winner.

Serena Williams [Images] won the title for the third time last year and looms as Henin's biggest danger this month.

The American caught everyone napping when she arrived ranked 81st in the world but no-one will be surprised if she wins again this time after turning up early to play at Hopman Cup in Perth.

"Last year was cutting it a bit close," she said. "It definitely pays to be here early."

The Russian revolution that has swept women's tennis has not quite reached Australia yet but 2008 could be the year.

The Australian Open remains the only grand slam tournament yet to be claimed by a Russian woman and leading the charge are Maria Sharapova [Images] and Svetlana Kuznetsova.

Sharapova made the final last year while Kuznetsova was runner-up to Henin in New York and is ranked second.

"I'm playing a little bit different and I've improved some things that I was working on in pre-season," Kuznetsova said.

"I think I've matured and I'm just analysing more what I'm doing during the game.

Among the biggest movers in the rankings last year were the Serbian pair of Jelena Jankovic and Ana Ivanovic, now third and fourth.

Neither has won a grand slam title yet but both see the Australian Open as their chance for a breakthrough.

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