Schwank, seeded eighth in the clay-court tournament, lost the first set 6-0 but completely turned his game around and lost just three games the rest of the way in a 0-6, 6-1, 6-2 win over Guillermo Coria.
Sixth-seeded Agustin Calleri had an easier time in his first-round match, dispatching Jurgen Melzer, 7-6 (7-3), 6-4. Also Tuesday, Yuri Schukin defeated Carlos Berlocq, 4-6, 7-5, 6-3, and Lukas Rosol topped Martin Fischer, 6-2, 6-4.
Two matches were suspended because of darkness after rain delayed play. Fifth-seeded Simone Bolelli was tied with Mischa Zverev, 6-7 (6-8), 6-4, and Brian Dabul led Denis Gremelmayr, 6-3, 5-5, when play was called.