Tokyo (AFP) - Top-seed Caroline Wozniacki survived a nail-biting scare Friday against Angelique Kerber of Germany at the Pan Pacific Open, advancing to a semi-final showdown against Belinda Bencic.
However, the tournament's defending champion and second-seed Ana Ivanovic will not be moving forward after losing 7-6 (7/5), 6-3 to Dominika Cibulkova, who is now set to face Agnieszka Radwanska in the semi-finals.
Wozniacki, the former world number one, clinched a 6-2, 2-6, 6-3 win over Kerber, who has won six of their previous 10 encounters.
The Dane comfortably overpowered her fifth-seed rival in the first set.
But the second set went to the German left-hander, who consistently delivered sharp shots deep into corners, forcing Wozniacki to run along the baseline.
But Wozniacki, who won the Pan Pacific Open in 2010, remained calm and picked up the pace toward the end of the second set, before firing off blistering shots to win key games in the third.
"I think we both played really well (in the third set). It could have gone both ways, but I won the most important points. I am very happy about that," Wozniacki said.
The victory sets up a semi-final match against eighth-seed Bencic, who beat Spain's third-seed Garbine Muguruza 7-6 (7/1), 6-1.
The 18-year-old Swiss has stacked up impressive wins this year by beating the likes of Serena Williams and Simona Halep.
She has won all of her three encounters against Wozniacki in 2015, including a victory in August in Toronto.
Meanwhile, world number 12 Ivanovic's campaign to defend the Tokyo title was shattered by Cibulkova, who also beat the Serb at the US Open.
Ivanovic said she felt confident going into the match, but Cibulkova appeared prepared to fight back, preventing her opponent from taking control.
Cibulkova exuded confidence and maintained pressure with her forehand, while Ivanovic failed to find her rhythm.
"She was reading the game really well. I thought it was a high-level match," said Ivanovic, who said it was difficult to find where to land her serves because the Slovak "was reading my serves really well".
"I was feeling really good on court. I did everything perfect today. I was really really tough," Cibulkova said, adding that she has fully recovered after foot surgery in February.
"I didn't play for four months and it's never easy to come back," Cibulkova said. "So now everything is good. I am so happy."
She will now face Radwanska of Poland, the 2011 Pan Pacific winner, who beat Czech fourth-seed Karolina Pliskova 7-5, 6-2 in their quarter-final.