Petra Kvitova and Maria Sharapova will contest an intriguing Australian Open semi-final after both women secured straight sets victories from their last eight encounters.
Wimbledon champion Kvitova struggled to find her rhythm, but overcame a spirited challenge from unseeded Sara Errani to win 6-4 6-4. It was not as easy as the scoreline suggests with the second seed having to battle back from 4-1 down in the second set before rattling off five straight games.
Prior to her quarter-final match, Kvitova had spent less than five hours on court during the tournament, but the 21-year-old was made to battle for an hour and 51 minutes on Rod Laver Arena before progressing to the last four.
"I expected [it] to be very tough - she played very well today and before," said Kvitova of her opponent.
"She has a very flat shot and plenty of spin to my backhand so I had to concentrate and think about tactics."
Kvitova will take on Sharapova in the semi-final after the Russian progressed courtesy of a routine 6-2 6-3 win over compatriot Ekaterina Makarova.
The 2008 champion took just 87 minutes to complete the match, breaking her opponent in the fourth game of the first set then breaking once again in the seventh.
Makarova took the initial advantage of the second set after breaking in the third game, but Sharapova hit back immediately with a break of her own in the next game. The world number four then secured the decisive break in the sixth game to claim victory.
Following Caroline Wozniacki's exit at the hands of Kim Clijsters, the world number one spot is up for grabs with both Kvitova and Sharapova in contention.
If Kvitova wins the Australian Open or loses to Clijsters, who takes on Victoria Azarenka in the other semi-final, in the final then she will be crowned the new number one, while Sharapova or Azarenka will move to the summit if either win the tournament.