"I didn't think I would have done as well as I have", she said.

No. 1 seed Serena Williams faced a challenge but ultimately was too much for Maria Sharapova.

Nevertheless, the world number one spoke of her need to play at a high level against Sharapova, speaking of the "fire and intensity" needed to beat a fellow elite player.

Federer crushed sixth-seeded Czech Tomas Berdych 7-6 (7-4) 6-2 6-4 in his quarter-final earlier on Tuesday to progress to the last four at a major for a mind-boggling 40th time.

Williams began in ominous fashion breaking the Pole's serve in the first game with Radwanska's lack of power highlighted by the blistering nature of the American's returns. "I can beat all the guys on tour", Federer told reporters.

Serena Williams put in a almost flawless performance to reach the Australian Open final, crushing Agnieszka Radwanska 6-0 6-4 in Melbourne on Thursday.

The six-time Melbourne Park champion heaped more misery on her long-time rival 6-4, 6-1, with the Russian fifth seed stretching her demoralising unbeaten run against the American great to 12 years.

"I haven't practised yesterday, I didn't hit a tennis ball", Djokovic said.

"I think if you're serving maybe 180 (km/hr) against somebody else compared to Serena, that's an ace", Sharapova said.

Williams said she had "no idea" whether she went on court against Sharapova with a mental edge but added: "There's something about her game".

Five-time champion Djokovic, after beating No. 7 Kei Nishikori 6-3, 6-2, 6-4, still has a daunting semifinal match against Roger Federer, who has won four of his 17 Grand Slam titles in Australia. She'll travel to Moscow for Fed Cup but does not intend to play, and then, "I don't see myself playing anything before Indian Wells". She broke back to make it level-pegging at 2-2 as the Russian's serve faltered. But he played a good level.

The only potential cloud on the horizon for Williams at this stage of the tournament is her health.

Sharapova plans for a light February: Nothing is set in stone, but Sharapova said she plans on dedicating the month to getting her forearm healthy.

Last week, the BBC and BuzzFeed News published reports saying tennis authorities failed to thoroughly investigate evidence of match-fixing involving a core group of 16 players who have ranked in the top 50 over the past decade. Williams saved it, and another before sealing the match with a big serve-forehand drive combo to glide into her 30 grand slam semi-final. A lot of these players would have shared a number of tournament wins in any other era but have had to watch as Serena continues to prove her greatness. "She's been playing really well towards the end of the year, and already this year she's been very consistent. Personally, I didn't think I'd be playing at this age", she said as she guns for a seventh Australian Open crown. I feel like I'm competitive at the top.

"She presents a completely different game, an extremely exciting game".