Carlsbad, CA (Sports Network) - Former U.S. Open champion Samantha Stosur posted a first-round victory Monday at the $795,000 Southern California Open tennis event.

The fifth-seeded Australian handled American Varvara Lepchenko 7-5, 6-1 on the hardcourts at La Costa Resort and Spa.

This week's top seed is 2013 Australian Open champion and 2012 U.S. Open runner-up Victoria Azarenka.

Slovakian Dominika Cibulkova, fresh off her title last week in Stanford, topped reigning Wimbledon champ Marion Bartoli in last year's Carlsbad finale.

This week's winner will claim $125,000.