The victory becomes the highlight of what has been a torturous comeback for the former world number one, who returned to tennis in April after being banned for testing positive for metabolic modulator meldonium at last year's Australian Open.
Sharapova's game is not yet firing on all cylinders but the Russian's competitive fires still burn bright ands he broke Halep to open the third set then grimly hung on for the win, dropping to her knees and bursting into tears as the Romanian's return sailed long.
There is undoubtedly a pressure to try to live up to the ranking and for Pliskova that means attempting to go one better than previous year at Flushing Meadows, when she lost to Angelique Kerber in her first grand slam final. But in the third, Sharapova regained control by going ahead 3-0, using her power to keep two-time French Open runner-up Halep under pressure.
"My reaction was normal, because this year I had very tough draws every time nearly", said Halep, who was on the court practicing when she learned of her first-round matchup.
Halep has nothing to hang her head about despite an early exit from the season's final Grand Slam.
Halep even reacted after finding out that she will play the 2006 US Open victor, and she considered a great challenge against Sharapova whom she had never beaten. She made it very tough for me to be able to get any easier points.
"From the second I found out I was playing Simona, I was actually getting my nails done, I got my phone out and I pulled up YouTube videos of our matches", she explained. "But I think I give everything I had". It's a little bit of a different situation.
Predictably Sharapova, the champion at Flushing Meadows in 2006, mixed a huge number of winners with even more unforced errors but it was enough for the 30-year-old to seal a memorable victory on her return to the big stage.
The French Open denied Sharapova a wildcard and she missed Wimbledon with a thigh injury, but US Open officials offered her a wildcard as "a past US champion who needed the wildcard for entry into the main draw", according to a tournament statement. "My serve was very bad today".
"I felt like going into this match, I knew my game plan".
That said-we all know she's unsafe in any form. "I would not say it's that open". It was a good match. I was upset about it because I really wanted that first practice on centre court. "From the moment that I've been here, I've really understood what this means to me, to be back".