Fifth seeded Albert Montanes of Spain defeated Philipp Petzschner of Germany 2-6 7-5 6-2 to advance to the second round of the Mercedes Cup on Monday.

Another German Florian Mayer stunned sixth seeded compatriot Philipp Kohlschreiber 6-4 6-2.

“I think I played really fast and very flat, and I think he doesn’t like my game. The altitude here, he missed a lot of points and that was the key today.” said Mayer.

Mayer next faces Guillermo Garcia-Lopez, who prevailed against Spanish qualifier Ivan Navarro 4-6 6-3 6-2 in two hours and 17 minutes.

Seventh seeded Gilles Simon of France battled past wild card Dustin Brown 6-3 3-6 7-6(1).

Juan Ignacio Chela downed Eduardo Schwank 6-2 7-5 in all Argentine encounter.

Daniel Gimeno-Traver ousted defending champion Jeremy Chardy 7-5 6-7(6) 6-3 to set up next round clash with top seeded Nikolay Davydenko.