Dechy, a wild card entry, topped China's Shuai Peng 6-4, 7-6 (10-8) and Razzano upended No. 8 seed Alona Bondarenko of Ukraine 6-2, 4-6, 7-5.
Also, in a second-round match, fourth-seeded Elena Dementieva of Russia bagged a 7-6 (9-7), 6-2 win over Petra Kvitova of the Czech Republic and No. 7 seed Agnes Szavay of Hungary needed more than two hours to beat Italy's Tathiana Garbin, 6-3, 4-6, 6-2 and advance to the quarterfinals.
Dementieva was the highest of the first four seeds receiving byes into the second round.
The 2008 Open de Gaz winner will earn a first-place check of $95,500.