Ace! Linda Noskova is on the board in this tie-break.

Linda Noskova takes a couple of paces inside the baseline to attack a short return but skews her cross-court backhand well wide. Quite grim.

Six set points for Aryna Sabalenka.

Two forehand return errors from Linda Noskova. Aryna Sabalenka is in complete control of this tie-break.

Ohhhhh, an untimely double fault from Linda Noskova, dumping her second serve into the base of the net.

Aryna Sabalenka follows a deep return with a forehand, taken at shoulder height, into the opposite corner.

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

You can feel the energy shifting. The level of tennis is starting to rise, it's really engaging.

I'm not sure who is going to come out on top.

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Aryna Sabalenka forces a backhand error.

Linda Noskova has really grown into this set, manipulating Aryna Sabalenka around the court to open up the space for a down-the-line backhand winner. 15-0.

She follows a short return into the net and buries a smash winner before smacking an ace down the T for 40-0.

Aryna Sabalenka nets a simple forehand. We're going to a tie-break.

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

Noskova is almost starting to look like the better player.

Just a little grin from Linda Noskova as she stretches to reach a wide serve and lands a backhand winner around the net post.

But it's an otherwise routine hold to 15 for Aryna Sabalenka.

Noskova will once again have to serve to stay in the set.

An ace for Linda Noskova is followed by an angry forehand return winner from Aryna Sabalenka - 30-all.

Noskova pings an ace out wide and then clenches her fist as Sabalenka nets a backhand on game point.

That's three games in a row for the sixth seed, who trailed 5-2.

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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 player's 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.

Image source, Getty Images

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.