Copenhagen: German qualifier Mona Barthel stunned third seed Bethanie Mattek-Sands 1-6, 6-3, 6-4 on Friday to reach the Copenhagen WTA semi-finals where she will tackle world number one Caroline Wozniacki.
While Barthel has collected her first two wins over top 50 players this week - she also upset No.5 seed Barbora Zahlavova Strycova - she will have a tough task ahead of her in Wozniacki.
"I didn`t even expect to be in the semifinals, and playing a No.1 is what every player wants, so I`m excited and have nothing to lose. I want to enjoy the match tomorrow," said Barthel.
After a very tough second round match Wozniacki was in top form on Friday, crushing No.8 seed Alberta Brianti in just 55 minutes, 6-0, 6-1.
"I played really, really well today," Wozniacki said. "I was aggressive, came to the net and served well. The crowd was amazing and really helped me."
Saturday`s other semi-final will see Czech fourth seed Lucie Safarova taking on Croatia`s Petra Martic.
Safarova beat China`s Zhang Shuai 4-6, 6-0, 7-6 (7/5) while Martic also needed three sets to beat Alona Bondarenko of the Ukraine, 6-4, 3-6, 6-3.