Top seed Amelie Mauresmo moved into the quarter-finals of the Diamond Games in Antwerp with a 7-6 (8-6) 7-5 win over French compatriot Virginie Razzano.
Mauresmo was too strong for French compatriot Virginie Razzano
Third seed Nadia Petrova beat fellow Russian Vera Zvonareva 7-6 (7-2) 6-4.
Petrova, who is going for back-to-back titles after winning in Paris last week, will next meet compatriot and seventh seed Anna Chakvetadze.
Elena Likhovtseva progressed when fourth seed Elena Dementieva withdrew because of illness trailing 6-2 1-1.
Eighth seed Ana Ivanovic of Serbia beat Nathalie Dechy of France 6-3 6-7 (2-7) 6-2 in the day's final match.