The five-time Grand Slam winner went down a quick break in the first set before revving up to claim the opener while playing in her third event since last month's end of a 15- month doping ban.
"It felt slow and the conditions are quite different to Madrid," said the three-time Italian Open champion yesterday. "It certainly took a few more games than I would have liked to get used to. But once I did, I felt like I took care of the second set quite well."
The former No 1'a ranking has recovered into the 200s and a semi-final this week would put her into the main draw for Wimbledon.
Sharapova came through a hic-cup near the end, losing serve as she prepared to wrap it up while leading 5-1, but recovered in the next game to emerge the winner.
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Sharapova is still waiting to hear if she will receive a wild card entry into Roland Garros starting a week from Sunday; that news will come on Tuesday, when she is otherwise engaged laying her second-round match.
"Winning matches will get me places, so if that's where it got me today, then I will take it. The fact that I'm back and playing three weeks in a row now and three events in a row for me is a big deal. That's my focus."
The match began unsteadily, with three breaks of serve in the first 17 minutes, McHale took an early 3-1 lead. But the rhythm steadied as the experienced Sharapova pegged back her opponent and got to work to sweep the first set from the back foot.
"At this point it's week to week. I certainly have expectations of myself just because when you have accomplished things and when you have won big events and you have been number one, you know that feeling.
"That feeling ultimately stays inside of you and you know how good it feels and you know what you work for.
"I would love to experience those feelings again. Of course, that is my goal. Every week is important, and I treat every match -- you know, I might have not played my best tennis, but I set up an opportunity to play another match and to hopefully improve in that match, and that's what I need."
Sam Querrey upset French 11th seed Lucas Pouille 7-6 (8/6), 7-6 (10/8).
Tomas Berdych, the number 12, defeated German Mischa Zverev 7-6 (9-7), 6-4; Jan-Lennard Struff put out Australian Bernard Tomic 6-7 (6-8), 6-1, 6-4.
Former US Open winner Juan Martin del Potro staged a comeback to oust Grigor Dimitrov 3-6, 6-2, 6-3, winning with seven aces after more than two hours.