Tokyo - Second-seeded Karolina Pliskova used a strong serve to help overpower Magda Linette of Poland 6-2, 6-1 on Wednesday to advance to the Pan Pacific Open quarter-finals.
After coasting through the first set, the Czech player broke her opponent with a backhand to the corner in the sixth game before serving out to win in just over an hour at Ariake Colloseum.
Pliskova, who had eight aces against Linette, will face either seventh-seeded Angelique Kerber or Daria Kasatkina in the quarterfinals.
"My serve was working well and my shots had great depth," Pliskova said. "I played against her in New York so knew what to expect. She didn't play her best game today and I was able to take advantage."
Anastasia Pavlyuchenkova of Russia also advanced with a 6-4, 4-6, 6-2 win over China's Wang Qiang.
Wimbledon champion and top-ranked Garbine Muguruza of Spain was scheduled to face 2016 Rio Olympic gold medalist Monica Puig later on Wednesday.
Singles results from the WTA Pan Pacific Open in Tokyo on Wednesday (x denotes seeding):
Garbine Muguruza (ESP x1) bt Monica Puig (PUR) 6-4, 6-0
Karolina Pliskova (CZE x2) bt Magda Linette (POL) 6-2, 6-1
Anastasia Pavlyuchenkova (RUS) bt Wang Qiang (CHN) 6-4, 4-6, 6-2