MELBOURNE, Jan 28: Serena Williams says she is impossible to beat at times, and there are a few people who might now be tempted to agree.

The former world number one has silenced the critics who suggested she is a spent force by advancing to an all-American final at the Australian Open, where she plays top seed Lindsay Davenport here on Saturday.

As much as anything it is the manner in which six-time grand slam title winner Williams won through to her showdown with Davenport that should eradicate any lingering question marks over her competitive hunger.

Facing match point on three occasions in her semi-final with Maria Sharapova, she stared down the challenge nervelessly and clawed her way back from the brink of defeat for a 2-6, 7-5, 8-6 victory.

The 23-year-old American insists she has nothing to prove to anyone, and has bristled throughout the past fortnight at the notion her tennis star is on the wane as she chases her first grand slam title since Wimbledon in 2003. But she admitted Friday that coming through her ordeal of fire against Sharapova, who had beaten Williams in the Wimbledon and WTA Championship finals last season, had been doubly satisfying.

"When you're winning matches 6-2, 6-1 you feel better - you're not sore, you feel fresh, you're body's good," Williams said. "But when you're winning 8-6 in the third after saving three match-points, it's even better.

Whether Williams will be at her best against Davenport is another thing altogether. But Davenport, who defeated Williams in both of their meetings last season, has got her own problems.

She staggered through her semi-final with France's Nathalie Dechy, flopping over the line with a 2-6, 7-6 (7/5), 6-4 win. But she played poorly, committing 52 unforced errors and 10 double faults.

"My game's a little bit off from where I'd ideally want it to be, but it's there," Davenport said. "I look at it like I need to play better than I've played to be able to win, and I know I can do that." -AFP