Wozniacki converted six of nine break points in a match that lasted just 44 minutes at Utsubo Tennis Center.
The U.S. Open finalist will face Canada's Aleksandra Wozniak in the quarterfinals. Sixth-seeded Wozniak struggled past Taiwan's Chang Kai-chen 7-5, 7-6 (2).
American veteran Jill Craybas recovered from a shaky start for a 2-6, 6-2, 6-0 win over France's Mathilde Johansson.
Craybas will face third-seeded Australian Samantha Stosur, who defeated Japan's Akiko Morigami 6-1, 6-2.