Melzer blitzed Igor Kunitsyn 6-1, 6-1 in 55 minutes. Melzer was good on just half of his first serves but still didn't face a break point and lost six points over seven service games.
He cashed in five of his nine break chances.
Wild-card entrant Mate Pavic ousted local favorite and fourth-seeded Robin Haase 6-4, 7-5 (7-2). The pair combined to win about 70 percent of the points on serve. Pavic, No. 640 in the world and in his first main draw match of the year, had the lone break in the match.
Qualifier Philipp Petzschner easily handled tournament defending champion Dmitry Tursunov 6-4, 6-2 by not dropped serve in the 67-minute match.
Tatsuma Ito capped Monday's action with a 3-6, 6-3, 7-6 (7-2) victory over Marton Fucsovics in a tight 2 1/2-hour match.
Other first-round play saw Leonardo Mayer beat Mikhail Ledovskikh 6-4, 6-2; Benoit Paire stop David Goffin 6-1, 6-4; Alejandro Falla get by Ruben Ramirez Hidalgo 6-4, 6-4; Paolo Lorenzi defeat Ivan Dodig by the same 6-4, 6-4 score; and Olivier Rochus advance when Malek Jaziri retired with Rochus up 6-3, 4-0.