The four-time Grand Slam champion fired off 20 winners and four aces to set up a second-round meeting with Australian Daria Saville.
Swiatek said that her tank was “pretty empty” after losing in the Montreal and Cincinnati semifinals earlier this month, but she showed no lack of vigor as she opened her US Open campaign with an ace and blazed through the first set.
The Polish player showed only brief signs of vulnerability early in the second set, as she began to accrue more unforced errors and had to claw her way back from triple break point in the first game.
But she reminded the crowd at Flushing Meadows why she has been No. 1 since April 2022 as she hit an unreturnable backhand shot to break Peterson to love in the fourth game, amid a 10-point winning streak.
Peterson, who only produced two winners across the match, never regained her composure and Swiatek pumped her first after closing out the match with a scorching backhand down the line.
“I really wanted to play solid and start [the] tournament with everything that I focused on [in practice],” she said in on-court remarks.
“I just feel happy that with all the pressure and expectations I can just have fun on court.”
Masarova converted all three break-point opportunities she had during the 87-minute encounter to secure her first career win over a top-10 player.
Information from Reuters was used in this report.