Kvitova, Wozniacki advance; Errani exits New Haven

Four-time champion Caroline Wozniacki and third-seeded Petra Kvitova landed in the quarterfinals, while top-seeded Sara Errani suffered a second-round upset Wednesday at the New Haven Open, a final U.S. Open tune-up.

The fourth-seeded Wozniacki defeated Italian qualifier Karin Knapp 6-1, 7-5, while the former Wimbledon champion Kvitova fought off American qualifier Alison Riske 7-6 (7-5), 4-6, 6-3 on the hardcourts at the Connecticut Tennis Center at Yale University.

The former world No. 1 and former U.S. Open runner-up Wozniacki captured this New Haven event four years in a row from 2008-11.

Meanwhile, Russian Ekaterina Makarova doused the 2012 French Open runner-up Errani, of Italy, 7-5, 6-1, while sixth-seeded American wild card Sloane Stephens slipped past German Julia Goerges 7-5, 2-6, 6-1.

Makarova's quarterfinal opponent on Thursday will be surging Romanian Simona Halep, who came from behind to beat Spaniard Carla Suarez Navarro, 3-6, 6-4, 6-1, on Day 4. The 21-year-old Halep is seeking her fourth title in seven events.

The 2013 New Haven titlist will earn $117,000.