Kohlschreiber, who was a semifinalist in the event last year, was played fairly even through two sets by Cedrik-Marcel Stebe before finishing off a 6-4, 3-6, 6-1 victory.
Kohlschreiber didn't face a break point outside of the second set -- when he lost two of five such opportunities for Stebe -- but totaled four breaks in the match. He won two-thirds of the points in the decisive set.
Seventh-seeded Alexandr Dolgopolov was the only seeded player on Monday's schedule and needed to come from behind before advancing with a 6-7 (4-7), 6-4, 6-4 win over Robin Haase.
Qualifier Jan Hernych advanced after a tough 6-3, 6-7 (5-7), 7-6 (10-8) win over Sergiy Stakhovsky. He fought off four break points in the third set before taking the extended tiebreaker.
Also Monday, Ivan Dodig edged Pere Riba 7-6 (7-4), 7-6 (8-6),Lu Yen-hsun topped Jarkko Nieminen 7-6 (7-2), 6-3, Igor Andreev took out Potito Starace 6-4, 6-4 and Tobias Kamke advanced when, after he took a 4-3 lead in the first set, Julian Reister retired.
Top-seeded Roger Federer goes against Lleyton Hewitt in his first-round match. That is a rematch of the 2010 Gerry Weber title match, which Hewitt won in three sets.