Vienna, Austria -- (Sports Network) - Olympic silver medalist Fernando Gonzalez moved on, while top-seeded Swiss Stanislas Wawrinka suffered a first-round upset Tuesday at the $930,000 Bank Austria Tennis Trophy.

The second-seeded Gonzalez came from behind to beat Italian Simone Bolelli 4-6, 7-6 (7-2), 6-2, while Wawrinka was upended by German qualifier Philipp Petzschner 6-7 (5-7), 6-2, 7-6 (7-5) on Day 2 at Wiener Stadthalle. Wawrinka was last year's Vienna runner-up to Serbian Novak Djokovic.

Gonzalez will face rising Latvian Ernests Gulbis here on Wednesday.

Another upset came when Argentine Eduardo Schwank toppled seventh-seeded Frenchman Gilles Simon 4-6, 7-5, 7-6 (7-5).

Austrian crowd favorite Jurgen Melzer got past fading Croat Ivan Ljubicic 7-6 (7-3), 6-3, while Colombian lucky-loser Santiago Giraldo grounded Austrian veteran Stefan Koubek, a wild card this week, 6-1, 6-2. Giraldo replaced sixth-seeded Spaniard Tommy Robredo in the draw, as Robredo pulled out with a left hip injury. Ljubicic titled here back-to-back in 2005 and 2006.

In other opening-round action, German Philipp Kohlschreiber shut down France's Marc Gicquel 6-2, 6-2, Czech Radek Stepanek stifled Czech qualifier Pavel Snobel 6-4, 6-2 and the aforementioned Gulbis dismissed Italian Filippo Volandri 6-2, 6-3.