Caroline Wozniacki fought through an injury to her right knee Thursday to beat Dominika Cibulkova 6-2, 6-1 in the quarterfinals of the New Haven Open.
The third-seeded Dane improved to 20-0 at the Connecticut Tennis Center where she is the four-time defending champion and looking to become just the fourth woman to win the same WTA event in five consecutive years.
It was unclear Thursday if she would be able to continue her title defense.
Wozniacki said that after hitting a backhand return in the first game of the second set she felt a twinge in her knee that was serious enough to call for the trainer. After a Cibulkova double fault on the next point, Wozniacki walked to the chair umpire, motioned to her knee, sat down and grabbed a bag of ice from a cooler.
''I decided straightaway after I felt it,'' she said. ''I played one more point and decided I needed to see the trainer because I felt a sharp pain in there. I needed to treat it.''