Defending champion Iga Swiatek crushes Rebecca Peterson in US Open first round

Poland's world number one off to a flying start at Flushing Meadow

Iga Swiatek of Poland celebrates a point against Rebecca Peterson of Sweden during their Women's Singles First Round match. AFP

World number one Iga Swiatek got her US Open title defence off to a dominant start on Monday, flattening unseeded Swede Rebecca Peterson 6-0 6-1 to kick off the action in Arthur Ashe Stadium.

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 semi-finals earlier this month but showed no lack of vigor as she opened her U.S. 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 the world number one since April 2022 as she whacked across 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."

Elsewhere, Greek eighth seed Maria Sakkari crashed out in the first round following a 6-4 6-4 defeat at the hands of Spaniard Rebeka Masarova.

World number 71 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.

Meanwhile, there was a long overdue win for Dominic Thiem, who has had a troublesome wrist injury in recent times.

The 2020 US Open champion knocked out 25th seed Alexander Bublik in straight sets for his first opening round victory since the 2021 Australian Open.

Thiem said: "It was amazing. Today is pretty special you know. I haven't won a Grand Slam match for a very long time and I couldn't have wished for a better place like here with all the memories, with all the past experiences here. I'm super, super happy."