Volynets, a 23-year-old California native, put 87 percent of her first serves in play and won 81 percent of her first-serve points. She never faced a break point.

Three other US players earned victories on Monday. Robin Montgomery topped Bulgaria's Viktoriya Tomova 6-1, 6-3; Caroline Dolehide downed Italy's Elisabetta Cocciaretto 6-4, 6-1; and Caty McNally rallied past Ukraine's Anhelina Kalinina 4-6, 6-1, 6-4.

Also advancing were Australia's Ajla Tomljanovic, France's Varvara Gracheva and Russia's Veronika Kudermetova and Polina Kudermetova.

Copa Colsanitas Zurich

Rain wiped out the scheduled opening-day slate at Bogota, Colombia.

--Reuters—