Naomi Broady
Former British player on BBC Radio 5 Sports Extra and BBC Sounds

That is so tough for Svitolina, she has been playing her best tennis and it is still not enough.

Marta Kostyuk slams in an overhead to move just two points from victory.

A timely ace gives her three match points. What an impressive finish this has been by the 23-year-old.

It's a must-win service game for Elina Svitolina, that's for sure. But the confidence is oozing from Marta Kostyuk right now, and she is overpowering her compatriot in the closing stages of this contest.

Svitolina yields on the first of two break points and still hasn't held serve in this set.

With a third successive game, Kostyuk will now serve for a place in her first major semi-final. Can she hold her nerve?

Naomi Broady
Former British player on BBC Radio 5 Sports Extra and BBC Sounds

They are both just so aggressive behind the ball. The net is more in play today.

Is that going to prove the springboard to victory for Marta Kostyuk?

The 15th seed is the first to hold serve, six games into the decider, and now she can see the finish line!

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A few signs beginning to show now that these two are feeling the pressure of the occasion - most evident on serve - as both seek to become the first Ukrainian woman to reach the Roland Garros semi-finals in the Open era.

But between the tense moments we're still seeing some excellent shots. Kostyuk reaches 15-30 with a sublime forehand, and two break points as she slices in a volley.

A final drop shot completes the job for yet another break of serve.

Elina Svitolina finds the line after sprinting on to a forehand as she goes in search of another quick response.

That's 22 winners apiece from these two so far - but it's Kostyuk who has made 10 more unforced errors (34).

Svitolina arrives at another break point as Kostyuk misses her mark - and a poor volley by the 15th seed makes it four successive breaks of serve.

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Marta Kostyuk shakes her fist after rattling a backhand winner down the line as she makes a perfect start on Elina Svitolina's serve.

She increases the pressure on Svitolina once again by reaching break point, and is gifted another break as Svitolina double-faults.

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What a start to this deciding set.

Both players are a maintaining a high level but the tension is ramping up now.

Elina Svitolina gets an immediate break back as Marta Kostyuk blinks first in a baseline exchange!

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Having perhaps been somewhat unsettled by Elina Svitolina's aggressive style in that second set, Marta Kostyuk makes a lightning start to the third set as she races to a 0-40 lead and three break points.

Svitolina saves the first two, but Kostyuk pounces on a tentative second serve to make the breakthrough.

Naomi Broady
Former British player on BBC Radio 5 Sports Extra and BBC Sounds

This is a pretty quick-paced match.

A second set point for Elina Svitolina...

This time, it's hers! Marta Kostyuk nets and we are going to a decider on Court Philippe Chatrier.

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Naomi Broady
Former British player on BBC Radio 5 Sports Extra and BBC Sounds

I don't think Kostyuk can believe how well Svitolina is playing up at the net.

Hugeee cross-court backhand from Elina Svitolina, and it hauls Marta Kostyuk back from game point.

Svitolina then gets her reward for her continued willingness to get forward as she forces an error from Kostyuk on her compatriot's next game point, but Svitolina misses her first set point moments later.

Marta Kostyuk looks set to force Elina Svitolina to serve out the set at 40-15.

But she misses a backhand, before Svitolina takes full advantage of a look at a second serve and finishes the point with a slice that drops perfectly on the line. Deuce.

This is a different Elina Svitolina to the one we saw for much of the opening set, and there is currently no sign of her relinquishing her advantage here. Another hold of serve puts her a game away from a deciding set.

Marta Kostyuk digs in to hold from 30-30 after a double fault and maintain the pressure on Elina Svitolina.

That's the first tight game in a little while. Will we have another twist before the end of this set?

There has been a notable change in approach from Elina Svitolina over the first hour of this match. Where she was somewhat the more passive of the two players in the opening stages, she is mixing up her shots and another drop shot helps her edge closer to levelling the match.

Image source, Getty Images

Naomi Broady
Former British player on BBC Radio 5 Sports Extra and BBC Sounds

Whether Svitolina wins or loses this match, I think they will be showing her the highlights and telling her this is how she needs to play.