NEW YORK, NY, USA - No.2 seed Ashleigh Barty bounced back from a poor start to overcome Zarina Diyas 1-6, 6-3, 6-2 in the first round of the US Open, moving through in one hour and 41 minutes.

The Australian's only previous encounter with Diyas had also been a tight affair, a 7-6(3), 6-4 win in the second round of Kuala Lumpur in 2013, and after 28 minutes of struggling to find her range on either serve or groundstrokes Barty soon found herself a set away from a shock upset. But the 23-year-old's renowned problem-solving abilities came to the fore as she gained more and more control over her game as the match progressed.

Afterwards, Barty did not mince her words about her performance. "I just didn't give myself a chance in that first set," she said. "Sort of appalling, probably made a set's worth of errors. We were able to find a way after that to get into the match and be more patient and really just lock down and wait until I got the right balls and right patterns that I wanted. That was probably the biggest change in the second and third - I was able to get more of those patterns more regularly and in the end build pressure to create more opportunities to break."

Back in 2010, Diyas had announced herself on Tour in spectacular fashion, ousting Jelena Jankovic from Moscow three days after she had turned 17 in her first ever meeting with a Top 10 player. The Kazakh has only added one other such scalp in the subsequent nine years - over Andrea Petkovic in Dubai in 2015 - but despite the extended gaps between elite victories, she came out rallying with confidence against the former World No.1. Despite tallying only one winner in the first set, this should not be mistaken for a lack of aggressive play: the 2017 Tokyo champion was constantly moving the ball around the court and able to inject pace behind her forehand when needed.

In particular, Diyas would also target the shaky Barty backhand: three consecutive errors from that wing, on both the slice and the drive, sealed a first break for the unseeded player as the first hints of the upset began to brew.

"She was able to put the ball in an awkward position for me, in a position where I couldn't attack," Barty assessed her opponent's game. "I was a lot of the time staying neutral and then pressing to try and wrestle the control of the point in my favor - and made errors by doing that."

Matters did not improve for Barty as the opening frame began to get away from her. The forehand soon joined the backhand as a source of unforced errors - the Australian would total 19 in the first set - and a 25% first serve percentage allowed Diyas to swing freely on return. Another flurry of fine forehands - a sharp angle, a dropshot and another down-the-line - took Diyas to the double break.

By the time the Washington quarterfinalist moved up 5-0, she was so confident off the ground that she even willingly brought Barty, one of the best volleyers in the game, into net with a short slice to nail the pass; two games later, she coolly served the set out to 15.

The Roland Garros champion is an expert at making adjustments, though, and as she slammed two forehand winners to open the second set it was clear that she had put the woes of the first set firmly behind her. Though still not as consistent as at her best, Barty would manage to nearly halve her unforced error count to 10, and nearly double her first serve percentage to 49%. With increased security behind her delivery - the former World No.1 would not face a break point in the second or third set - a succession of confident holds provided Barty with a solid base from which to repair her game and begin dismantling that of her opponent.

To Diyas's credit, she was alert to Barty's raised level, and responded well. Upping the pace on her groundstrokes and making her way to net to knock off a series of swing volleys, the 25-year-old valiantly stuck with Barty for most of the set. But it was the Miami and Birmingham champion who struck in the eighth game, flashing the kind of forehands that had been absent in the first set to reach break point - whereupon it was Diyas's own forehand that ultimately went awry. A game later, a fourth ace would level the match for Barty in emphatic fashion.

Firmly in control, Barty asserted her authority over her lower-ranked opponent throughout the decider. Now landing 65% of her first serves and dictating off both wings to take her total of winners to 27, she was unrecognisable from the player who had begun the match - as was Diyas, who began to over-press and descend all too rapidly into error, including on a number of significant putaways. A tight tussle in the fourth game proved crucial: Barty would capture the first break of the final set on her fourth break point as a Diyas forehand went long.

From there, Barty would roll through the remainder of the match. From 3-2 up, she reeled off 16 of the last 20 points of the match as Diyas, who had only hit eight unforced errors in the first set, reached a final tally of 31. Up next for Barty in the second round will be Lauren Davis, who defeated qualifier Johanna Larsson 7-5, 6-2.

"Lauren's obviously one of the tougher challenges, playing an American in the US Open," mused Barty. "And she's been on a little bit of a heater over the past couple of months and had some good wins and coming back to some of her best stuff. It's a match that we will prepare as best as we can for tomorrow and then Wednesday we'll be ready to go."