The German claimed the first set but his opponent, ranked 39 places below him, took the second before the world number 22 closed out a 6-2 3-6 7-5 win.
France's Benoit Paire was another seed to advance as he beat Pole Michal Przysiezny 6-4 6-2 but Dutch eighth-seed Robin Hasse was beaten 4-6 7-5 7-6 (7/4) by Guillermo Garcia-Lopez of Spain.
Slovakia's Lukas Lacko progressed as he beat home hope Jose Statham 6-3 6-1 while Lu Yen-hsun of Chinese Taipei was a 7-5 7-6 (9/7) victor over Dutchman Igor Sijsling.
American Donald Young beat Argentina's Federico Delbonis 7-5 6-2 and Spaniard Roberto Bautista Agut claimed a hard-fought 6-1 3-6 6-4 win against countryman Daniel Gimeno-Traver.
American Bradley Klahn took the first set 7-5 against Germany's Daniel Brands but was trailing 4-2 in the second when play was stopped due to rain and they will resume on Wednesday when Cypriot Marcos Baghdatis will also take on the USA's Steve Johnson.