The 14th-ranked Radwanska is seeking her first WTA title in three years and is enjoying a solid season. She reached the quarterfinals of the Australian Open and the fourth round at the French.

American Christina McHale beat Croatia’s Mirjana Lucic 6-1, 6-0 and will meet the winner of a later match between No. 8 Dominika Cibulkova of Slovakia and Japan’s Kimiko Date-Krumm.

Canadian Rebecca Marino beat American Coco Vandeweghe 6-4, 6-4 to earn a second-round match against third-seeded Marion Bartoli.