Petra Kvitova of the Czech Republic returns a shot to compatriot Barbora Zhlavova Strycova during the Connecticut Open at the Connecticut Tennis Center at Yale, yesterday in New Haven.The reigning Wimbledon champion Kvitova advanced to the semi-finals with a 6-4, 6-1 triumph over Strycova. The fourth-ranked Kvitova next will face Australia’s Samantha Stosur, who ousted Belgium’s Kirsten Flipkens 6-3, 4-6, 6-3 in the final warm-up event for the US Open, which begins on Monday.