Wozniacki, looking for her first tournament title since August 2011, beat seventh-seeded Klara Zakopalova 6-2, 6-3. Wozniacki piled up five breaks and won 56 percent of the points when receiving serve. She did, however, lose her serve once in each set.
She heads into Saturday's semifinals against No. 8-seed Ekaterina Makarova, who won two-thirds of the points in rolling to a 6-1, 6-1 quarterfinal win over Maria Jose Martinez Sanchez. Makarova dropped just 11 points over seven games serving.
The other semifinal sends third-seeded Kaia Kanepi against No. 6-seeded Varvara Lepchenko. Kanepi had 10th-game breaks in each set of a 6-4, 6-4 win over Kiki Bertens and Lepchenko battled Tamira Paszek for 2 hours, 45 minutes before emerging with a 4-6, 7-6 (7-3), 6-4 victory.
Wozniacki is 4-0 lifetime versus Makarova, including a pair of straight-set wins this year. Saturday will mark the first meeting between Kanepi and Lepchenko.