Piers Newbery
BBC Sport at Roland Garros

A man with a bright yellow Romania football shirt, 'Hagi, 10' emblazoned across the back, does his best to lift his compatriot's spirits. "Si-mo-naaaaa!" he screams, to the delight of the couple sitting in front of him. For one of the biggest matches of the year, with the number one ranking and a Grand Slam title up for grabs over the next two days, the atmosphere has been a bit flat. Only now are the crowd getting involved, and it's Romanian fans who are shouting loudest.

Karolina Pliskova cracked 13 winners in that second set, compared to just two from Simona Halep.

The same again will see her reach a first Roland Garros final...

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Chanda Rubin
American former world number six on BBC Radio 5 live sports extra

That was the perfect way to close out a set. Pliskova served a really smart game, moved it well around the box. I have been impressed with the way she has moved forward and taken balls out of the air. That has elevated her game.

Pliskova may have missed the chance to take the second set in that previous game, but she doesn't this time.

The Czech has cut down on the unforced errors, finding a couple of forehand winners to take this match into a decider.

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Wow, this is ball-striking that anyone would be proud of. Pliskova wallops a forehand from the baseline that fizzes cross-court and out of Halep's reach.

A set point... saved.

The Romanian needs to keep this set going as long as possible - you fancy Pliskova to tire quicker - and that is what she does as she battles back to hold.

Chanda Rubin
American former world number six on BBC Radio 5 live sports extra

That was a massive service hold for Pliskova. It was such an important game, trying to consolidate. To come back from 0-30 will take a bit of steam out of Halep. A massive game for multiple reasons.

"Hold serve, Karolina, hold serve." That's what Pliskova will be saying to herself.

But she gets the jitters, more unforced errors helping gift two break-back points to Halep.

The Czech second seed digs deep again, saving those, then saving another couple in deuce.

Over to you then Miss Halep. Can you hack the pressure? The Romanian serving to stay in the set...

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Right then! Pliskova wakes up on Halep's serve, taking more risks and moving forward more. It pays dividends.

The Czech lands three break points when she sees a forehand winner disappear past the baseline.

She loses the first as Halep battles back, but the Romanian can't control the next rally and sends a backhand wide.

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Pliskova is starting to find rhythm on her serve, the problem is she can't knock Halep's out of tune.

After Halep levels up at 2-2, Pliskova crashes down an ace - her fifth of the match - to kick off the fifth game.

Pliskova sticks her foot on the gas, upping the speed and not allowing Halep a sniff.

Good recovery from Karolina Pliskova. A double fault from the Czech hauls Halep level at 30-30, but Pliskova digs deep to avoid another wobble.

A cracker of an ace wide - which whizzes past Halep's eyeline quicker than a peregrine falcon - clinches the hold.

Image source, Getty Images

Chanda Rubin
American former world number six on BBC Radio 5 live sports extra

The decision-making within these points are so critical. Pliskova was in a neutral position in that point and Halep was able to take the game.

For the first time in, well, a while, the Halep serve faces an examination. Pliskova creams a forehand to level at 30-30, but then proves to be her own worst enemy.. another unforced error.

That poor backhand is followed by a look to the heavens. She knows. Halep goes on to hold.

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Pliskova gets the second set up and running - and she is instantly back under the cosh.

A 40-15 lead quickly become deuce, Halep reading the Czech's serves beautifully, before Pliskova manages to ride the storm and bash down a forehand winner to hold

The stats clearly show where Pliskova's problems lie: she has won 48% of first serve points and has made a whopping 26 unforced errors.

Basically Halep is a returning machine and Pliskova is getting anxious.

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Chanda Rubin
American former world number six on BBC Radio 5 live sports extra

Halep has got right back to business, throwing in first serves and she got the reward.

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No surprise, really. Simona Halep has been in command of this opening set since winning that early break, and clinches the first set with a minimum of fuss.

The Romanian quickly earns two set points thanks to more unforced errors off Pliskova's racquet.

Two becomes one, as the Spice Girls once said, Pliskova leaning into a serve to drill in a cross-court backhand winner.

But another unforced error - a forehand going long - sees Halep home.

Chanda Rubin
American former world number six on BBC Radio 5 live sports extra

It is interesting to see the contrast of styles - Pliskova is a big hitter and Halep a great mover.

Ricology: Pliskova needs to find her rhythm & the heavy forehand winners will follow. Very strong from the byline

Pliskova saves her skin again. She's hanging on. Halep has another set point, but the Czech second seed has her on the run, planting another forehand winner to safety.

Pliskova grows in confidence, hitting deep to test Halep's defensive powers, and the Romanian can't cleanly return two forehands.

However, she is still going to serve out for the match...

Image source, Reuters

Halep sees a set point disappear as quickly as it arrives, Pliskova staying toe-to-toe in a baseline rally before stepping in to put away a forehand winner.

Deuce...

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Halep's serve look solid as she moves within a game of the opening set. The 2014 finalist races 40-0 ahead, Pliskova offers some resistance with a winning forehand volley, but Halep batters a forehand winner down the line. Can she wrap this up by breaking Pliskova's serve?

Image source, Reuters