Sabalenka shrugs in disbelief after cupping an effort into the tape, before leaking another forehand long as Fernandez holds.

What a point!

It had a bit of everything - fierce groundstrokes, a neat drop shot, an undercooked lob and a thumping overhead winner from Sabalenka.

Fernandez isn't put off by that, she throws in another drop shot off the next that has Sabalenka scrambling to no avail and then whips the crowd up with both arms in the air. Pantomime stuff.

Great retrieving from Fernandez but the Canadian eventually leaves too much court for Sabalenka to thrust a backhand into. The second seed then throws down her fifth double of the match.

An ace follows, not a bad way to hold.

Aryna Sabalenka plays a neat wide serve-backhand winner combo, before raising her arms into the air and trying to generate a response from the crowd. There's a gentle flutter of cheers and applause.

That noise is cranked up when she miscues off the next - Leylah Fernandez is the firm fans' favourite in New York.

Aryna Sabalenka thrashes her racquet into the ground before showing a banana more mercy - the second seed gets a code violation for her troubles.

She tugs it into the guts of the net! Needed a touch more composure there, Sabalenka. That's deuce and Fernandez picks off her opponent with a delightful dash and drop volley at the net.

She's even framing them in now... a forehand loops high and drops on to the chalk. A big hold.

Every point is a right tussle at the moment. Sabalenka challenges a call but the crowd's reaction will tell you it is out. 30-30. But then Fernandez dices a forehand long... break point Sabalenka.

Tremendous from the 19-year-old! The New York crowd are on their feet... she's hitting her spots and Aryna Sabalenka cannot handle it. Leylah Fernandez breaks back.

Image source, Getty Images

Lovely slice from Fernandez and she follows up with an even better passing backhand winner to leave Sabalenka stranded at the net. Wonderful shot.

The second seed double faults and all of a sudden Fernandez has a chance to break back.

Leylah Fernandez seems to generate so much speed from so little backlift on her groundstrokes.

She edges to 40-0 before Aryna Sabalenka arrives at the party. Fernandez makes sure her opponent doesn't even have time to reach the dancefloor with a punchy serve to hold.

Snappy tennis from Sabalenka, whipping her way to 30-15 before Fernandez engineers a deep return that forces the second seed long. The 23-year-old watches a high ball drop out of the New York sky, spins and flicks away a backhand winner on her way to a hold. She backs up the break.

Aryna Sabalenka breaks to love with a thunderous backhand winner! That's the way to start a comeback...

Some serious hustles from the second seed. Three break points to start the second set.

The dream just continues for Leylah Fernandez, but can she maintain that momentum going into the second set? The 19-year-old immediately faces some jeopardy as Aryna Sabalenka comes out fighting at 0-30.

Wow! The teenager comes from three games down to take the opening set. Sensational from Leylah Fernandez.

Image source, Getty Images

Double fault from Sabalenka this time! Leylah Fernandez has three set points.

Uh oh. Double trouble for the 19-year-old but it remains delicately poised after Sabalenka fires a backhand long.

Fernandez roars in delight as a ball travelling her direction drops long, before scrambling her way back to 3-2.