If, as Andy Roddick had suggested, the gap between Roger Federer and the rest of the tennis world was closing, the American was deeply deluded.

The world number one put a shell-shocked Roddick firmly in his place with a clinical 6-4, 6-0, 6-2 execution to storm into the Australian Open final on Thursday.

Maria Sharapova gatecrashed Kim Clijsters's farewell party to set up a historic final showdown with Serena Williams.

But the day belonged to the Swiss master.

Federer protected his aura of invincibility in devastating style to march into his seventh successive Grand Slam final, equalling the record of Australian Jack Crawford, set in 1934.

"It's just unreal. I'm shocked myself, I don't know what to say," said Federer, who is in hot pursuit of a 10th Grand Slam crown.

"I played incredibly well but the tournament isn't over yet, so let's not get carried away."

Roddick had swaggered on to court with great expectations of narrowing his lopsided 1-12 career record against Federer as he beat the Swiss in an exhibition tournament just 12 days ago.

That dream was crushed in 83 brutal minutes.

Fans were left gasping as it seemed whenever Federer touched the ball, it turned into an outrageous winner, shots that most of his rivals can only dream about.

Roddick was left reeling when he lost 11 games in a row and no matter how hard he tried, it appeared as if he was facing an opponent from a different planet.

With almost nothing going his way, a frustrated Roddick sent his racket flying as he slammed a ball into the stands.

As Federer ended Roddick's public humiliation with a forehand crosscourt winner, he dragged the cheering crowd to their feet.

The display will no doubt leave the Swiss's potential final opponent, Fernando Gonzalez or Tommy Haas, to endure a couple of sleepless nights before Sunday's showpiece match.

YOUTHFUL EXUBERANCE

Comeback queen Williams proved that she still belonged among the elite, dousing the youthful exuberance of Czech 10th seed Nicole Vaidisova 7-6, 6-4 with a ruthless exhibition of power hitting.

Sharapova become the first Russian woman to reach the Australian Open final with a 6-4, 6-2 victory, denying Belgian Clijsters a fairytale run in her last appearance at Melbourne Park.

"I'm going to miss it, it's been a pleasure to come here. It's always a lot of fun and I'm sorry I couldn't come up with a better match today," Clijsters said with a rueful smile as the fans gave her a standing ovation.

While Sharapova will be the bookmakers' favourite for the title, seven-times Grand Slam champion Williams should have the crowd on her side after her stunning passage to Saturday's showpiece match.

The American entered the tournament ranked 81st in the world but proved she still possessed the appetite for winning big titles by trampling over five seeds.

PLUCKY CHALLENGE

She needed six match points to kill off the plucky challenge of Vaidisova and greeted her moment of triumph by arching backwards before letting out an almighty roar of relief.

"I'm so excited (about the final) I have nothing to lose, I'm having a lot of fun. I'm back in the top 20 and that means so much to me," squealed the 25-year-old American, champion at Melbourne Park in 2003 and 2005.  

Williams has certainly been incredible herself as not many thought she would survive the first couple of rounds, let alone reach her 10th Grand Slam final.

The players also laughed off suggestions that a male supporter in Williams's entourage had tried to distract Vaidisova with the glare from his watch caused by the reflecting sun.

"Ha, ha, ha, ha... that's the most outrageous thing I've ever heard. As if anyone would do that on purpose. That's so funny," Williams told reporters.

Vaidisova added: "I really didn't notice that."

Williams will be aiming on Saturday to become only the second unseeded woman to win the Australian Open crown in the professional era after Chris O'Neill in 1978.

She will have to overcome the mighty challenge of world number one elect Sharapova who will seek to win the one major trophy to have slipped through the grasp of Russian women.

The US Open champion had won just two of her six previous meetings with Clijsters but did not let that, or sentimentality, blur her focus.

Sharapova turned villain in front of "Aussie Kim's" adopted fans, shoving the popular Belgian towards the exit with a dogged display from the baseline.

Chilean Gonzalez, seeded 10th, plays German Haas, 12th, in the second men's semi-final on Friday.