In the women's semifinals, Williams will be facing fourth-seeded Agnieszka Radwanska, who beat No. 10 Carla Suarez Navarro 6-1, 6-3.

Six-time champion Williams has never lost a semifinal or final at the Australian Open, and is an overwhelming favorite to win her seventh title at Melbourne Park and claim a 22nd major.

"Physically I'm feeling a lot better, mentally I needed that break after the Open", she said, but "I didn't think I would do this well this fast". "He's one of those guys who make you a better player, he's beaten me on the biggest courts around the world".

It meant the five-time Grand Slam winner's demoralising jinx against Williams remains intact, dating back to 2004 when she last beat her in the Wimbledon final.

Williams put a lot of pressure on Sharapova for the break, eventually converting her 4th break point in the game to take the set 6-4.

"It's going to be tough no matter what; whenever you're stepping onto the court - especially for me, I feel like everyone plays their hardest when they play me. She makes you work, and that's inspiring". That only came after Williams had already broken though, and by the ninth game of the set she would do so again. Her downfall started in an epic semi-final at the 2005 Australian Open, with the American scraping home in a 2-6, 7-5, 8-6 thriller. She became the first WTA player since Amelie Mauresmo in 2005 to clinch the WTA Finals crown without yet being a Grand Slam champion.

Williams, the oldest world number one in Women's Tennis Association history, is often a slow starter and Sharapova made the most of it to hold for a 2-0 lead as the top seed made a string of errors. Williams took the next three games, closing the match with a love hold to be one match away from tying Steffi Graf's Grand Slam winning streak at 22.

The Swiss, 34, fell behind early in the first and third sets but hit back immediately both times and was dominant for the most part on serve.

Serena Williams (x1) bt Maria Sharapova (x5) 6-4, 6-1.

Williams said she wasn't aware that she had won the Australian Open all six previous times she won her quarterfinal match, "but that's good".

"She's a great defender and a great girl", Williams said of the Pole.

The world number one called for the doctor at the changeover but powered on stronger than ever in the second set, making it 12 games out of 15 as she sealed victory after one hour and 32 minutes.

"I've been playing this week aggressive and I didn't start that way so after the first set I just wanted to play the way that got me to the quarter finals".

"When I play better, when I'm forced to play better, I don't know, I do well".

"I think so. There was just no mistake", she said. It blows my mind right now.

The Toronto native and his doubles partner Radek Stepanek dispatched Pablo Cuevas and Marcel Granollers 7-6(11), 6-4 in semifinal action at the grand slam tournament on Thursday.

"I'm going to be ready and whatever happens, happens".