Anna Chakvetadze sprung the first major surprise in the Pilot Pen tournament, ousting fourth seed Nadia Petrova.

Petrova started in the most emphatic fashion, taking the first set against her unseeded Russian compatriot 6-0.

But Chakvetadze hit back to take the next two sets, 7-6(4) 6-4 to progress.

Sybille Bammer is also through in the women's draw, beating Spain's Anabel Medina Garragues 7-5 6-4, as is Alona Bondarenko, who saw off Meghann Shaughnessy 4-6 6-3 7-5.

In the men's first round American Taylor Dent surprised Ivan Ljubicic to make the next stage.

Dent, the world number 202 eased his way past the Croat 6-3 6-4.

Paul Capdeville beat Jarko Nieminen 7-5 6-3, Leonardo Mayer bested Denis Istomin 6-2 6-4 and Florent Serra 6-3 6-3.

Janko Tipsarevic is through after Fabio Fognini forced retirement and Marc Gicquel is through having cruised past Martin Vassallo Arguello.