Errani was the runner-up at the French Open last month and is ranked a career-high No. 9 this week. She won this clay tournament in 2008.
Also, Irina-Camelia Begu of Romania rallied to beat Lourdes Dominguez Lino of Spain 3-6, 6-1, 6-4; and Spanish qualifier Estrella Cabeza Candela eliminated Italian wild card Maria Elena Camerin 7-6 (3), 7-5.
In a first-round match suspended due to darkness on Tuesday, eighth-seeded Barbora Zahlavova Strycova of the Czech Republic beat Silvia Soler-Espinosa of Spain 7-5, 7-6 (3).