Caroline Wozniacki will meet Ana Ivanovic in the Pan Pacific Open after beating Spaniard Garbine Muguruza in Tokyo.
Dane Wozniacki, who was recently beaten by Serena Williams in the US Open final, took two and a half hours to beat Muguruza 6-4 2-6 6-2.
Third-seed Ivanovic needed to battle from behind against German Angelique Kerber to win 7-5 6-3.
After her victory, former world number one Wozniacki told reporters: "I kept fighting. It was a very competitive match.
"I just tried to stay in there and in the end I think maybe I had a little bit more energy than what she had."
Both Wozniacki and Ivanovic have previously been ranked number one in the world.
