Grand Slam feud

She couldn't bear to watch as sister Serena stood on the brink of defeat against Kim Clijsters - but Venus Williams' eyes are now firmly on the prize at the Australian Open.

The greatest sibling rivalry in the history of tennis plays out its latest instalment here Saturday when the Williams sisters go head-to-head in a Grand Slam final for the fourth consecutive time.

Having finished on the losing side of the net to her younger sister at Roland Garros, Wimbledon and US Open last season, second-seeded Venus is now determined to halt the sequence of defeats.

On Thursday Venus buried her head in her hands while watching helplessly from the players' box at the Rod Laver Arena as her sister trailed 5-1 in the final set of her semi-final with Clijsters.

"I just felt so sad for her at 5-1," said Williams.

"But I knew that if she could just win one game she would do a lot better and she did. She's a regular Houdini," she added, following Serena's remarkable 4-6, 6-3, 7-5 win over Clijsters.

The two sisters teamed up again on Friday when they claimed their sixth Grand Slam doubles victory.

But sisterly love gets pushed to one side on Saturday as Venus attempts to wreck her sister's hopes of completing the 'Serena Slam', by adding the Australian Open to her collection.

"On the court I'm a competitor, no matter who it is, I hate to lose," Venus said. "The same with her - maybe her even more."

"Off the court we're sisters again. If she were to twist her ankle on the court, of course I'd be concerned but I would still have to go out and hit the next shot.... that's the way it is."

Venus' last victory in a Grand Slam came at the 2001 US Open, crowning a two-year period when she dominated the game.

Last year's emergence of Serena, and a lengthy end-of-season break spent "living life and hanging out", prompted many to wonder whether the elder Williams still had the desire to be the best.

Venus is adamant the fire is still there.

"I've always wanted to win titles, especially if it's a Grand Slam," she said, following her 6-3, 6-3, demolition job on Justine Henin-Hardenne in Thursday's semi-finals. "I'm just as hungry, just as motivated."

Serena, who will become the first women since Steffi Graf in 1994 to hold all four Grand Slam titles at the same time if she wins on Saturday, is in no doubt that her sister plans to knock her off her perch.

"She's never sat down and told me, 'Serena, I'm going to take No.1 away from you," Serena said. "But I'm sure that's what she wants to do.

"She's working hard, she's playing really well. She is just on a different level from a lot of the girls and everyone else - including me sometimes.

"When I'm practising with her I'm like 'I don't know how I was ever able to beat her,'" she said, adding that last year's defeats have made Venus more keen than ever to win in Melbourne.

"I think it definitely makes a person more determined," she said. "I think she really, really wants another Slam."

Both players have performed patchily throughout in Melbourne, with Serena being taken twice to three sets.

Venus started slowly but appears to be hitting form at the right time, and crucially has rediscovered her biggest serving game en route to the final.

In her quarterfinal against Slovakia's Daniela Hantuchova Wednesday, she sent down one booming ace that clocked 201kp/h, just outside her five-year-old record of 205kp/h set in Zurich in 1998.

Venus' serve could be crucial against her sister, who possesses arguably the most potent forehand return.

Both players, meanwhile, have sought in Melbourne to augment the raw power of their respective games with more deftness. Venus has caught the eye by making forays to the net more frequently, a tactic she believes can make her an even more formidable opponent.

The winner of Saturday's match will take an outright lead in head-to-head meetings between the two. Of 11 matches, five have been shared between the players, with one walkover going to Serena because of injury.