Sharapova was playing her first competitive match in 15 months after being hit with a doping ban when testing positive for meldonium, and just edged through in straight sets.
The Russian responded well after losing her first service game to take a tight opening set, before she broke her Italian opponent twice in the second to set up a clash with Ekaterina Makarova in the next round.
There was no noticeable bad reception for the 30-year-old, who spoke of her delight at making her return.
"I've been waiting for this for a long time,” she said. "It's the best feeling in the world, those first few seconds before you enter the arena. To know you were walking back out there was special.
"I spent a long time without hitting any balls. I didn't know when I would be back. I went to school for a little bit, I grew my business and had a normal life. I put the racquet away for a little bit.
"I felt I had to grow as a person and I think I've done that. But this is what I've done for so long. I'm a competitor - that's when I'm at my best."