A quick start to the tie-break for Sabalenka as she edges ahead and has the serve.

Deuce again, it's getting tense but Leylah Fernandez comes through to hold.

Saved! Good depth from Fernandez and Sabalenka rattles the net. Deuce.

The fluff seems to glide off the strings of Fernandez, although she packs a pretty punchy serve.

Sabalenka has plenty of punch of her own and all of a sudden a miss from the Canadian hands her set point.

Huge ace followed by an even bigger roar as Sabalenka holds serve to put the pressure back on her opponent.

It's big and brave from Aryna Sabalenka but not always on the money. The Belarusian takes a deep breath after cupping a backhand into the tape. 30-30.

Leylah Fernandez picks off her opponent with a neat backhand only to then go long. Not to worry, the Canadian dusts herself down and flicks a winner into the opposite corner. She holds.

Aryna Sabalenka thunders down a succession of absolute cannonballs and complements those serves with some huge hitting. She holds.

What a return! And what a change of momentum.

Some great tennis on show and Fernandez might just sense a chance at 15-30.

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Good save from the teenager. A whipping serve and effective groundstroke combo.

Fernandez holds and the New York crowd go wild.

Aryna Sabalenka clenches her fist in celebration after a punchy backhand winner down the line but Leylah Fernandez throws in a different serve off the next to keep her opponent guessing.

It's a break point chance for the second seed though.

Here come the crowds - they must've beaten the traffic, got a hot dog or had a sufficient toilet break.

They've arrived in time to witness some wonderful tennis, 15-15.

Great hitting from both players, but Sabalenka just cranks through the gears at the vital moment - and then double faults... wow. Fernandez breaks back.

Double fault from Aryna Sabalenka as she slips to 0-30, and suddenly Leylah Fernandez senses an opportunity - a snappy return brings up three break points.

In the wheelchair competition, Britain's second seed Alfie Hewett is a set and a break up in his men's quarter-final against Frenchman Nicolas Peifer, leading 7-5 2-0 in the second set.

In the women's draw, compatriot Jordanne Whiley is a set to the good against Japan's Momoko Ohtani, however she has just been broken in the second set and Ohtani will now serve to level the match.

Earlier, Gordon Reid defeated the Netherlands' Tom Egberink 6-1 6-4 to reach the men's semi-finals.

Leylah Fernandez throws down a wide-kicking ace, that'll do the job. It's followed by another, picking out the exact spot she eyed up before her ball toss.

This is better from the 19-year-old, and a second serve ace to polish off the hold!

The only thing louder then Aryna Sabalenka's forehand is the cheer to her box after winning a spectacular point. She soars to a quick hold.

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Can Leylah Fernandez get on the board? The left-hander starts well, backing up a pacy serve with some baseline groundstrokes, before forcing Aryna Sabalenka into the net.

That whips the crowd up and the applause ripples out again after the youngster wins another gruelling exchange. There she goes, the 19-year-old is off the mark.

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Zing. 118mph ace from Sabalenka. Fernandez didn't even see it. The Belarusian mixes it up with another powerful serve that this time tenderises the body of her opponent.

She polishes up a love hold in smart fashion to back up the break a moment ago.