The clay-court tournament also lost its top-seeded player as Andreas Seppi withdrew because of a groin injury.
Calleri, who won the Austrian Open in 2006, was dumped 6-4, 6-4 by Guillermo Garcia-Lopez in the biggest upset of the 16-match card Tuesday. Also, eighth-seeded Olivier Rochus was beaten, 3-6, 6-4, 6-0, by Ivo Minar
With all of Monday's matches rained out, organizers squeezed the entire first round in Tuesday.
Second-seeded Rainer Schuettler advanced to the second round, rallying for a 3-6, 7-6 (7-5), 6-2 win over Andreas Beck in a near upset. But No. 4-seeded Potito Starace, who topped Santiago Giraldo, 6-1, 6-2; fifth-seeded Eduardo Schwank, who beat Michael Berrer, 6-4, 6-1; No. 6-seeded Jurgen Melzer, who stopped Luis Horna, 6-3, 6-1; and seventh-seeded Juan Martin Del Potro, who beat Josselin Ouanna, 6-3, 6-3, all advanced in straight sets.
Devilder's win was a 6-3, 6-3 decision over Matthias Bachinger, who replaced Seppi in the draw.