World number one Victoria Azarenka saw off a spirited display from Svetlana Kuznetsova to keep the defence of her Australian Open title on track.
Kuznetsova, a two-time former grand slam champion, proved she is over the knee surgery which forced her to miss the second half of 2012 with a wonderfully creative display - mixing clever angles with raw power.
But it was not enough to derail Azarenka who, having edged the first set, ran through the second to register her 12th successive win in Melbourne, 7-5 6-1.
Azarenka said: "She played really well throughout the whole match. I know what kind of tennis she is capable of and in the beginning it took a little bit of adjustment because she has a very different game. I am glad I could produce my best tennis when it was needed."
Azarenka needs to retain the title on Saturday night to stand any hope of keeping her number one ranking and it looked as though that position was under severe threat in the early stages as Kuznetsova came out firing, displaying the kind of tennis which saw her win the 2004 US Open and 2009 French Open crowns.
This was no typical crash, bang, wallop encounter, with Kuznetsova particularly inventive. Deft with the drop shot and imaginative from mid-court, she tried to move Azarenka off the baseline from where she can do the most damage with her brutal groundstrokes.
And for a while it worked. The Russian broke for 3-1 and after holding, an upset seemed on the cards. But Azarenka roared back, playing some smart tennis of her own.
She broke back for 3-4 and then ramped up her performance level even further at 5-5, with a big forehand on break point edging her ahead for the first time in the match.
She served it out and then maintained the momentum by breaking in the opening game of the second.
Kuznetsova hit back immediately but she could not win another game as the top seed advanced to a last-four clash with Sloane Stephens.