Ashleigh Barty has made a confident start to her US Open campaign with a storming first-round win over Tunisian qualifier and former junior doubles partner Ons Jabeur.

Australia’s 18th seed spent just 65 minutes on court in stifling hot conditions, seeing off Jabeur 6-1 6-3 to book a second-round date on Wednesday with veteran Czech Lucie Safarova or Croatian Petra Martic.

Still recovering from a lingering virus that forced her withdrawal from last week’s lead-up event in New Haven, Barty said it was vital to set the tone early.

“Obviously it’s pretty brutal conditions out there – nice and warm and humid and pretty energy-sapping really, a bit like Brisbane to me,” the Queenslander said.

“It was nice to get off to a good start and kind of consolidate in the middle of the second set there.

“I’ve known Ons since we were very young and knew what she’s capable of. She’s a very exciting player, has a lot of shots and has the ability to take the game away from you.

“So it was important that I made her play a lot of balls today and really work for every point.”

Victory for Barty over Safarova or Martic could set up a third-round showdown with dual grand slam champion and former world No.1 Garbine Muguruza.