Errani, the tournament's No. 1 seed, defeated Barbora Zahlavova Strycova 6-3, 6-2, keeping Zahlavova Strycova on the defensive throughout the match. Errani had 19 break chances and finished off seven over nine games of them. She won about 60 percent of the points when receiving serve.
Errani advances to a match Friday against seventh-seeded Silvia Soler-Espinosa, who was up 6-1, 1-0 when Mirjana Lucic-Baroni retired. Soler-Espinosa had won about three-quarters of the points serving when the match was stopped.
Wednesday's other second-round winners will have to wait until Thursday play to learn their opponents.
Dinah Pfizenmaier easily got past Anabel Medina Garrigues 6-1, 6-1 without dropping serve and Renata Voracova defeated Corinna Dentoni 7-5, 6-1.
Third-seeded Kristina Mladenovic took a 6-1, 7-6 (7-5) first-round win over Maria Joao Koehler. Mladenovic goes against Estrella Cabeza Candela Thursday, with the winner facing Voracova in the quarterfinals Friday.