Henin piled up five service breaks in a 6-3, 6-3 win over Roberta Vinci. It was far from a perfect effort by Henin, who had six double faults and dropped her own serve twice.
She advanced to a quarterfinals match against Kristina Barrios, who came from behind for a 3-6, 6-2, 6-3 win over Sybille Bammer. Barrios overcame seven double faults and five service breaks in the victory.
Another quarterfinals pairing was set when fourth-seeded Yaroslava Shvedova and No. 5-seeded Alexandra Dulgheru both won in three sets.
Shvedova rallied for a 2-6, 6-3, 6-2 victory over Anastasia Rodionova while Dulgheru took a 6-3, 2-6, 6-1 decision over Alla Kudryavtseva.
The other UNICEF Open quarterfinals have seventh-seeded Andrea Petkovic going against Sandra Zahlavova and Dominika Cibulkova meeting Kirsten Flipkens.