Annabel Croft
Former British number one on BBC Radio 5 Sports Extra 2

Isn't that incredible? Tennis is strange, it's so psychological, it doesn't take much for the balance to shift.

This is any players' set now.

Well, well. Aryna Sabalenka nets a forehand and is broken to 15.

How will she respond?

Annabel Croft
Former British number one on BBC Radio 5 Sports Extra 2

There is the first sign of just a few jitters appearing from Sabalenka.

There have been enough glimpses of what Noskova is capable of, the crowd are noticing as well.

The crowd applauds enthusiastically as Linda Noskova moves forward and powers into a driven cross-court forehand winner. They're urging the Czech on.

The following point, Aryna Sabalenka double-faults and lets out a roar of frustration. 15-30.

With a down-the-line forehand which kisses the corner of the court, Noskova has two break points.

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Linda Noskova comes through deuce at the first attempt, sealing an iffy hold with an ace.

Aryna Sabalenka will serve for the first set. She's only dropped five points on serve.

Better from Linda Noskova, making Aryna Sabalenka move as the pair engage in a rare baseline exchange before forcing the error from the top seed by coming on the approach.

Her next net approach, however, is quite dismal, tipping a backhand volley into the net for 15-30. Why she went for that stroke with two hands on her racquet, I don't know.

Sabalenka forces deuce with a booming backhand return.

Aryna Sabalenka eases through a hold to 15, including a well-executed kick serve which rises above Linda Noskova's head for 40-0.

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Annabel Croft
Former British number one on BBC Radio 5 Sports Extra 2

This is going a bit too quickly for Noskova. She needs to find a way to slow this game down.

It hasn't really lived up to expectation yet this match, has it? The atmosphere is quite quiet.

Aryna Sabalenka looks rueful as the two break points come and go in the blink of an eye.

Linda Noskova comes through deuce with a couple of big first serves, attacking a short return for advantage before nailing an ace down the T. A good recovery from 15-40 down and a confidence-boosting hold.

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Aryna Sabalenka is in the mood, gobbling up a slow wide serve from Linda Noskova and hammering home a cross-court forehand return winner for 0-15.

At 15-30, she attacks a timid second serve with her backhand and brings an error from Noskova, stretching to her left. Uh oh.

Aryna Sabalenka holds to 30. She'll be very happy with the opening 15 minutes or so of this match.

Annabel Croft
Former British number one on BBC Radio 5 Sports Extra 2

It's a bit staccato this start for Noskova.

Sabalenka will want to take advantage of the nerves down at the other end.

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Linda Noskova's serve is yet to settle, with a double fault sandwiched between aces for 30-all.

But she comes through to hold, Aryna Sabalenka trying to blast a couple of returns but putting the first into the net and sending the second long.

The Czech sixth seed is up and running.

Annabel Croft
Former British number one on BBC Radio 5 Sports Extra 2

Sabalenka has been so accurate with these serves. The aces that she's hit have been right to the corner junctions.

It feels like she's been out on the practice court, she's bringing a lot of consistency.

Aryna Sabalenka is so devastating when she steps inside the baseline to attack a short serve return, bruising a down-the-line backhand to level the game at 30-all.

Ace number two of the game (and three of the match) brings up game point. A second serve on to Linda Noskova's backhand - returned long - completes the hold.

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Linda Noskova saves the first break point but Aryna Sabalenka finds a winner out of nowhere on the second, going inside-out with her forehand after an exchange of lusty blows down the middle of the court.

Linda Noskova, by contrast, opens with a double fault.

A tame second serve is pounded back to the baseline by Aryna Sabalenka and Noskova's backhand goes into the net.

Another error, this time on her forehand.

Three break points.

Annabel Croft
Former British number one on BBC Radio 5 Sports Extra 2

Wow she could not have played a better first game than that.

I also think it sets the tone psychologically for the opponent.

What a perfect four points she's just made.

Aryna Sabalenka wallops a couple of first serves to race into a 30-0 lead, pounds a down-the-line forehand with Linda Noskova wisely scattering in the opposite direction, and closes out the hold with an ace out wide.

That couldn't have gone much better for the world number one.

Image source, Getty Images

Aryna Sabalenka leads the head-to-head 2-0, most recently beating Linda Noskova 6-3 6-4 in the semi-finals in Indian Wells in March.

Sabalenka will serve first on Arthur Ashe to get the US Open singles quarter-finals up and running.