Top-ranked Victoria Azarenka has withdrawn from the Italian Open because of a right shoulder injury.
Tournament organizers say Azarenka made the decision after routing Shahar Peer of Israel 6-1, 6-2 in the second round Wednesday night.
Azarenka has won four titles this year, including the Australian Open. She lost the Madrid Open final to Serena Williams on Sunday.
Her withdrawal means her scheduled opponent Thursday, 14th-seeded Dominika Cibulkova, advances to the quarterfinals.
This tournament is the last major warm-up for the French Open, which begins May 27.