The third seed rounded off a packed schedule on day two at Roland Garros in quick time to move through to a second round clash against Czech Tomas Machac.
Zverev, beaten in the French Open final last month, had lost his only previous match against Munar but was streets ahead on a warm evening on Court Philippe Chatrier.
Zverev is bidding to match Briton Andy Murray's feat of winning consecutive Olympic men's singles titles.