On a scorching Court Philippe Chatrier, Zverev needed just over two hours to see off world number 95 Bonzi on the opening day of the clay-court Grand Slam.
Zverev broke in the sixth game of the first set to take control.
The pair exchanged breaks midway through the second set, before Zverev pounced on his opponent's serve to get ahead 5-4, immediately sealing the two-set lead with a clean hold.
With the mercury tipping past 30C, Zverev raced through the final set to book his ticket into the round of 64.
"Very good start to the tournament, always nice to start with a straight-sets win," Zverev said on-court.
"(It was) all around a good performance, very happy with the start."
The 29-year-old German second seed will next face Czech Tomas Machac, who earlier beat Belgium's Zizou Bergs 6-4, 6-4, 6-3.