Bethanie Mattek-Sands advanced to the second round of the Generali Ladies WTA event by beating seventh-seeded Austrian Tamira Paszek 6-2 6-4 on Tuesday.
The 201st-ranked American converted her third match point when Paszek double-faulted.
Her next opponent is Carla Suarez Navarro of Spain, who defeated Magdalena Rybarikova of Slovakia 6-3 6-4.
Also, Mallory Burdette of the US beat Ksenia Pervak of Kazakhstan 6-3 6-4.
Pervak had lost in qualifying but replaced 2009 champion Yanina Wickmayer of Belgium, who pulled out shortly before the match because of exhaustion.
Dominika Cibulkova of Slovakia, who was seeded third and reached the final last year, withdrew from the event with a shoulder injury.