Alexander Zverev began his pursuit of a sixth title this year in Vienna with a hard-fought victory over Viktor Troicki.
The German won the first set 6-3 before Troicki claimed the second 3-6. However, Zverev was victorious by the third and final set 6-4.
He will now move into the last 16, where he will face France's Gilles Simon who beat Ernests Gulbis.
Simon, former world No.6, was rarely troubled during his first round encounter with wildcard entry Gulbis and he comfortably defeated the Latvian 6-3, 6-3.
The 32-year-old was joined in the second round by compatriot Richard Gasquet, who was equally emphatic in his opening match, taking just 66 minutes to dispatch experienced Spaniard Feliciano Lopez 6-2, 6-3.
Gasquet's next opponent is likely to be No.2 seed Dominic Thiem, provided that the Austrian doesn't suffer an early exit at the hands of Andrey Rublev.
Elsewhere, Philipp Kohlschreiber upset fifth seed John Isner 7-6 (1), 6-4 to set up a match against Pierre-Hugues Herbert.
Herbert beat Bernard Tomic 7-6 (3), 7-5 in a close battle and his victory over the Australian also ended the six-match losing streak he was previously on.