Justine Henin-Hardenne produced an improved display to beat Maria Vento-Kabchi of Venezuela in straight sets.
The Belgian world number one, who is making her comeback after missing 11 weeks with a virus, cruised through to the third round with a 6-2 6-1 victory.
She now faces Nicole Pratt after the Australian fought back to beat Tathiana Garbin of Italy 1-6 7-6 (7-5) 6-2.
Sixth seed Venus Williams cruised into the next round after an easy 6-0 6-0 win over Slovenia's Maja Matevzic.
French Open champion Anastasia Myskina of Russia, who dropped only one game in the first round, was taken to three sets by Kristina Brandi of Puerto Rico before winning 6-3 3-6 6-4.