MELBOURNE, Jan 23: Andy Roddick was granted his wish for the Australian Open on Tuesday when he booked a tantalising semi-final date with world No 1 Roger Federer.

Sixth seed Roddick showed there was no mercy when playing your friends as he flattened fellow American Mardy Fish 6-2, 6-2, 6-2.

But with a 1-12 record against the Swiss, Roddick will hope his dream encounter does not turn into a nightmare after Federer became the first player in the professional era to reach 11 successive major semi-finals with a 6-3, 7-6, 7-5 win over Tommy Robredo.

Serena Williams, meanwhile, needed every ounce of her competitive spirit to set up a last four showdown with Czech teenage prodigy Nicole Vaidisova.

Only Robredo's closest friends would have considered the seventh seeded Spaniard as anything other than roadkill on Federer's inexorable journey to a third Australian Open title.

He provided Federer with his sternest test yet as he broke the Swiss maestro four times, but facing a man who is in hot pursuit of a 10th grand slam title, Robredo simply did not possess the goods to derail him.

“I'm very happy to be through as it was a 'tough' straight sets,” Federer said courtside following the two hours 20 minute outing.

With a fired-up Roddick waiting to take him on, Federer knows he can not afford a repeat of the lapses in his next match.

“It's great to see Andy doing well. We've had some great battles and I'm looking forward to that match. He's in good form, so I better play well,” he said.

As a bleary-eyed Melbourne Park recovered from the epic Rafael Nadal v Andy Murray clash that finished at 0151am local time on Tuesday, Roddick provide the pick-me-up in the men's draw.

After coming through a five-setter against Mario Ancic, it was back to plan 'A' as Roddick tore apart unseeded Fish in three one-sided sets.

Fish had gone into the match rejuvenated by earlier wins over fourth seed Ivan Ljubicic and 16th seed David Ferrer, but Roddick served and blasted his way into the last four after just 87 minutes on Rod Laver Arena.

The American immediately had his next match in mind the moment he walked off the court.

“I'd like to play Roger,” said Roddick, who beat Federer in the Kooyong exhibition tournament 10 days ago.

“I've lost to him a bunch of times and he's a great player but I feel like I'm improving a lot right now, I'd love to play him.”

Williams had to rely on her battling instincts to prevent Shahar Peer from crashing her comeback party.

Peer, 19, was already in uncharted territory for an Israeli woman by reaching the last eight of a slam and she had one foot in the semi-finals until the seven-time major winner shut the door in her face.

Unseeded Serena, champion in 2003 and 2005, won 3-6, 6-2, 8-6 in two hours and 34 minutes after Peer had come within two points of victory.

Peer, showing the toughness one would expect from someone who started mandatory army training in 2005, bossed the match in the early stages but Williams looked the only winner at the death.

“I'm the ultimate competitor,” she told the Rod Laver Arena crowd. “I love to compete, I always have even if I'm playing cards or signing autographs the quickest.”

She now faces another formidable opponent in the last four after 10th seed Vaidisova triumphed in the battle of the Czech teenagers.

The mature 17-year-old waltzed past Lucie Safarova 6-1, 6-4 to reach her second career Grand Slam semi-final.

It took just 71 minutes for her to beat the conqueror of champion Amelie Mauresmo, but she now faces her stiffest test against the improving American.

Another success story from coach Nick Bollettieri's production line in Florida, Vaidisova was clearly impressed by one trait she picked up there -- single-mindedness.

“Everywhere I go I have a Czech mind. It's not like when I go to Asia I try to change to my Asia mind, then use my Australia mind. I'm definitely influenced by America, but still keeping my one Czech mind,” she said.

Results (prefix number denotes seeding):

Men’s singles:

Quarter-finals: 1-Roger Federer (Switzerland) beat 7-Tommy Robredo (Spain) 6-3, 7-6 (7-2), 7-5; 6-Andy Roddick (US) beat Mardy Fish (US) 6-2, 6-2, 6-2.

Women’s singles:

Quarter-finals: Serena Williams (US) beat 16-Shahar Peer (Israel) 3-6, 6-2, 8-6; 10-Nicole Vaidisova (Czech Republic) beat Lucie Safarova (Czech Republic) 6-1, 6-4.—Reuters