Chinese qualifier Zhang Shuai failed to make another breakthrough into the semifinals.
Zhang went down to another darkhorse, British player Joanna Konta, in straight sets 6-3, 6-1.
Zhang, who has never gotten this far at a grand slam event, says she is feeling the toll as well as the excitement of action from the past few days.
"Yeah, feeling so tired. Everything feeling very slow on court. Yeah. But in my heart I'm feeling I already win the tournament because I win seven match. Yeah, doesn't matter win, lose today, just keep going."
Zhang rolled over Madison Keys and second seed Simona Halep on her way to reach the quarterfinals.
Konta is no weak opponent, having sent home Venus Williams and China's Zheng Saisai in previous rounds.
She is the first British woman to be in the last four of a grand slam event in 30 years.
Konta will play Angelique Kerber for a place in the final.
Kerber had earlier downed Victoria Azarenka 6-3, 7-5.
Kerber says she is not too concerned about her opponent.
"Actually it doesn't matter against who I'm playing in the semis. I mean, who is in the semis played very good four matches actually, or five matches. I think I will just try to focusing on my game, as well. I mean, I will try to not thinking against who I'm playing. I will just try to focusing like today, to be aggressive, more focusing on my game, and then let's see how far I can get here."
Serena Williams and Agnieszka Radwanska set up the other semi-final yesterday.
Williams continues to eclipse Maria Sharapova, getting past her Russian rival 6-4, 6-1.
On the men's court,
Andy Murray squeezed past David Ferrer in four sets.
He next plays Milos Raonic who is the winner of a four-sets affair against Gael Monfils.
Novak Djokovic and Roger Federer earlier made it through to complete the other half of the semifinals.
In women's doubles,
Chinese pair Xu Yifan/Zheng Saisai were bounced from a set up to miss the final.