Fourth seed Gilles Simon was made to work by wildcard Maximilian Marterer before reaching the second round of the German Tennis Championships in Hamburg.
The French world number 39 was taken to three sets by the German hopeful but eventually prevailed 6-2 4-6 6-4 in just over two hours to set up a clash with Philipp Kohlscreiber or Andrey Rublev.
Another Frenchman, world number 40 Benoit Paire, also progressed in the clay-court event as he saw off Russian veteran Dmitry Tursunov 6-3 6-2.
Diego Schwartzman of Argentina, the sixth seed and world number 38, beat Austria's Andreas Haider-Maurer 6-2 6-3.
The host nation enjoyed some success with victories for German players Florian Mayer, Cedric-Marcel Stebe and Jan-Lennard Struff.
Another German, world number 170 Yannick Hanfmann, triumphed in the opening round of the Swiss Open in Gstaad, beating Argentina's Facundo Bagnis 6-3 6-7 6-4.
Uzbekistan's Denis Istomin overcame Italian qualifier Lorenzo Giustino 6-3 6-2 while Norbert Gombos of Slovakia won 7-6 6-2 against Japan's Taro Daniel.
Source: PA
