World number one Roger Federer is unfazed by Novak Djokovic's claim that he is beatable at this year's Australian Open.

The pair will meet in a hotly-anticipated semi-final tomorrow night in what is expected to be one of the matches of the tournament.

The Swiss maestro was far from his best in his quarter-final against American James Blake but held his nerve on the key points to go through 7-5 7-6 (7-5) 6-4.

''I've heard it before and don't read it anymore because it's the same thing over and over again,'' said Federer, who is into a record 15th straight grand slam semi-final.

''This is the way you're supposed to think out there. You are not coming here to lose in the first round.

''You're coming here to hopefully do well and then win the tournament if you're one of the top-ten guys.

''That's reality. That's nothing new. That's not cocky. That's confidence. That's just a normal tennis player.''

Federer pulled out of the warm-up event at Kooyong with a stomach virus, and speculation about his form heightened when he was taken to 10-8 in the fifth set of his third-round match against Serbia's Janko Tipsarevic.

Since then, he has not dropped a set in wins over 13th seed Tomas Berdych and now 12th seed Blake.

Federer insists he is looking forward to taking on the rising Serbian star in the semi-finals - a re-match of the 2007 US Open final which the Swiss won.

''I think when the top three, top four guys play against each other, it's always entertaining for both of us,'' he said.

''I think it's great that Rafa (Nadal) made it through as well, with Novak. It's good for tennis.''

Djokovic, the third seed at Melbourne Park, advanced earlier in the day with a 6-0 6-3 7-5 victory over Spaniard David Ferrer but admitted that nerves got the better of him towards the end of the match.

The 20-year-old failed to successfully serve for the quarter-final at his first attempt and came perilously close to being broken in his next service game before converting his fifth match point.

''It's really difficult sometimes to control your emotions in such big matches and important points,'' said Djokovic, who is aiming for a maiden grand slam title.

In his penultimate game, Djokovic bounced the ball more than 20 times in a bid to stay calm before serving.

''Since I bounce the ball more and more, people figure out that I'm nervous,'' said a smiling Djokovic. ''But in the end I served it out.''

After such a meteoric rise, Djokovic believes any further improvements in his game will be more incremental.

''I was working on my skills in the past couple of weeks. And I changed my strings and I'm feeling really well now,'' he said.

World number five Ferrer admitted he too had been tense on court, blaming nerves for his disastrous opening set.

Ferrer, who enjoyed a 3-2 record over Djokovic prior to Melbourne, had emerged victorious from the pair's most recent meeting in Shanghai but never looked like repeating the feat.

''I started very badly, very nervous. And maybe it was a problem in the first set,'' said Ferrer.

''When I lost the first set, in the second he played better with more confidence."

Promising youngster Daniel Evans maintained British interest at Melbourne Park by progressing through to the quarter-finals of the Junior Australian Open.

The third-seeded 17-year-old, who is based in Nottingham, saw off the challenge of America's Ty D Trombetta in straight sets to reach the last eight of a junior grand slam for the second time - having already done so at the US Open last season.

Evans' 6-3 6-2 victory has set up a clash with India's Yuki Bhambri and should he win, the world number nine would become the first British junior to reach the last four of a slam since Andy Murray triumphed at Flushing Meadow four years ago.