New Haven, CT -- (Sports Network) - Swiss veteran Patty Schnyder posted an opening-round win Monday at the $600,000 Pilot Pen Tennis event, a final U.S. Open tune-up.

The fifth-seeded Schnyder snuck past American wild card Jill Craybas 6-4, 7-6 (7-2) on the hardcourts at the Connecticut Tennis Center.

Also, seventh-seeded Frenchwoman Alize Cornet gained the second round after she outlasted Czech Nicole Vaidisova in a late two-set dandy, 6-3, 7-6 (10-8).

A Day-2 upset came when rising Dane Caroline Wozniacki took out eighth-seeded Slovakian Dominika Cibulkova 7-6 (9-7), as Cibulkova retired after the first set due to a heat-related illness.

In other first-round play, Italian lucky-loser Sara Errani outlasted American qualifier Mallory Cecil 6-2, 4-6, 7-6 (7-1); Aussie Casey Dellacqua drove out France's Virginie Razzano 6-3, 6-1; Romanian Sorana Cirstea came from behind to beat Russian qualifier Alla Kudryavtseva 4-6, 6-3, 7-5; and Slovenian Katarina Srebotnik fought back to dismiss Spanish qualifier Maria Jose Martinez Sanchez 6-7 (4-7), 6-3, 6-2.

Russian Svetlana Kuznetsova, who is not defending her title this week, topped Hungarian Agnes Szavay in last year's hardcourt finale here.

This week's winner will collect $95,500. The top seed is Russian Anna Chakvetadze, who will meet the aforementioned Dellacqua in the second round.