"I can't describe it; it's amazing to be in the semifinal," the Bremen-born seventh seed said of her quarter-finals win on Wednesday, adding that she'd told herself to "just go for it and beat her (Azarenka)."

Twenty-eight-year-old Kerber, who has never gone beyond the fourth round at Melbourne Park before, blasted past the Belarusian 6-3, 7-5, having lost all six previous encounters with her. The German clinched the match in one hour and 45 minutes.

"I tried to serve well from the first point and play more aggressive than the last few times I played her. This is an incredible feeling to play here on center court," she said of the experience.

She'll now play British hopeful Johanna Konta for a place in the final.

After winning the opening set lasting three-quarters of an hour, Kerber's quality shone through as she battled back from 2-5 down in the second set against a player who has been in superb form this season.

Azarenka had lost just 11 games in her four matches prior to meeting Kerber and was seen as the main threat to Serena Williams' relentless march to a 22nd Grand Slam crown.

But Kerber, who had a stellar 2015, winning four tournaments, second only to Williams' five, had other ideas to become the first German into the last four in 18 years. The last woman to achieve that was Anke Huber in 1998.

Williams brushed aside Maria Sharapova in her quarter-final and faces Agnieszka Radwanska on Thursday for a place in the decider.

In the men's, Novak Djokovic and Roger Federer are set to face each other in the semifinals.

World No. 1 and defending champion Novak Djokovic beat Kei Nishikori in straight sets 6-3, 6-2, 6-4 in Melbourne's Rod Laver Arena on Tuesday.

Federer, the world No. 3, had a more difficult time of it, needing two-and-a-quarter hours to get past sixth seed Tomas Berdych 7-6 (7-4), 6-2, 6-4.

mm/jr (AFP, dpa, Reuters)