Elena Rybakina hasn't taken that break kindly and comes out with intent, rattling off three successive points to get three break points.

Wow. A backhand down the line means Rybakina will serve for the set.

Image source, Getty Images

Emily Salley
BBC Sport at Wimbledon

Barbora Krejcikova lets out big roar and she shakes a clenched fist towards her team after finally getting on the scoreboard - breaking Elena Rybakina's serve in doing so.

That will do her the world of good.

Chanda Rubin
American former world number six on BBC One

High shot tolerance from Krejcikova - she got another break point. It was hard fought and she earned it.

Elena Rybakina has already got five aces under her belt in this match as she looks to quickly wrap up the first set.

But Barbora Krejcikova is starting to find her feet and manages to seal a much-needed break.

There's still a lot of work to do if she is going to claw anything back from this set but that has to be a big confidence-booster.

Image source, Getty Images

Emily Salley
BBC Sport at Wimbledon

After the longest ever women's semi-final at Wimbledon, there's still plenty of empty seats on Centre Court with fans popping out for a refreshment break.

The way this match if going, they might not make it back for the end.

A rapid start for Elena Rybakina.

Elena Rybakina already looks to be in full flow as she steps up over the baseline and places a forehand into the corner and out of Barbora Krejcikova's reach for a 30-15.

Krejcikova sends a backhand wide to hand Rybakina a chance for a double break.

Rybakina takes it.

This is looking ominous for Krejcikova.

Image source, PA Media

Emily Salley
BBC Sport at Wimbledon

Elena Rybakina may be the title favourite, but Barbora Krejcikova is no underdog.

Not only is Krejcikova a former French Open champion, but she's also got a 100% win record against Rybakina.

That was over two years ago, though, and the two wins came on hard courts.

Rybakina is off to an ideal start.

Chanda Rubin
American former world number six on BBC One

One of the keys to serving well is hitting the different areas of the box with a similar look - Rybakina has got the lot.

Elena Rybakina looks her swift hold with a 40-15 lead but an unforced error into the net allows Barbora Krejcikova back into the game.

Krejcikova lets out a scream after sending a cross-court backhand into the corner for deuce.

Rybakina, who lifted the Wimbledon title in 2022, saves two break points before going on to hold.

Could that SW19 experience prove key today?

Sam Smith
Former British number one on BBC TV

There is an ominous sound coming from the former champion Rybakina.

She is seeing it well and she's had her chance to break in this game. The ideal start for the former champion.

Some nerves from Barbora Krejcikova in just her second career Grand Slam singles semi-final?

A loose forehand from the Krejcikova hands Elena Rybakina has an early look at break point, but it's a great response from the Czech as her 99mph serve proves unreturnable. Deuce.

But Krejcikova can't save a second break point as her forehand drifts wide.

Image source, Getty Images

Chanda Rubin
American former world number six on BBC One

This could be a a tricky opponent for Rybakina.

Krejcikova has just enough variety, she can get the ball out of the strike zone of her opponents.

Rybakina puts her authority on this match and doesn't allow Krejcikova to dictate.

Elena Rybakina has only dropped one set so far at Wimbledon over the past couple of weeks and she settles into this match comfortably with a hold to 15.

Over to you Barbora Krejcikova.

Image source, EPA

Emily Salley
BBC Sport at Wimbledon

It's been a tough season for both these players.

Elena Rybakina has won three titles, but her season has often been disrupted by illness concerns that caused her to withdraw from Indian Wells and Rome - events where she was the defending champion.

Meanwhile, Barbora Krejcikova has struggled with a back injury and illness, winning just three singles matches in the five months before the Championships.

Given those circumstances, it's some achievement to be in a Wimbledon semi-final.

As Emily said (re 16:54), it's going to take something special to match the record-breaking semi-final we've just seen on Centre Court.

Elena Rybakina is on serve first as we get under way.

Marion Bartoli
Former Wimbledon champion on BBC Two

The main problem for Elena Rybakina is that her health doesn't allow her to be on the court.

Sometimes she could wake up and have zero energy. But, when she strikes the ball and her health is at bay she is an incredible tennis player - she makes it looks so easy.

Image source, Getty Images

Barbora Krejcikova started 2024 in decent form with a run to the quarter-finals of the Australian Open but a first round exit at the French Open - where she lifted her only Grand Slam singles title in 2021 - proved frustratng.

But the Czech has bounced back swiftly and is enjoying her best-ever run at Wimbledon with a place in the final up for grabs if she finds a way past fourth seed Elena Rybakina.

Krejcikova has already overcome two seeded players to reach this stage, beating 11th seed Danielle Collins and 13th seed Jelena Ostapenko.

The 28-year-old can also draw comfort from her head-to-head record against Rybakina, winning both previous encounters, although the most recent victory came in October 2022.

If Krejcikova does manage to make it three from three against the Kazakh, she will face Italy's Jasmine Paolini in Saturday's final.

Joe Rindl
BBC Sport at Wimbledon

We're racing through the first set on Court One where there's a party atmosphere in the stands.

After Marcus Willis was broken in the first set the British duo have been asking for more and more noise and the supporters are doing their best to deliver.

It's almost like the Euros as somebody above me shouts "C'mon England" which gets a laugh from Alicia Barnett on court.

Five rows in front of me is the noisiest section. That's where Willis and Barnett's friends and family are sitting.

Annabel Croft
Former British number one on BBC Two

Elena Rybakina has an early preparation and it's quite mechanical how she sets up, she uses her left hand to point and balance herself.

She is also very tall, but for someone that tall she uses her legs well to absorb and to stay low. That's important to do the grass and that's why Jasmine Paolini has done well.

You have opposites playing each other in these semi-finals which makes it very interesting.

Image source, Getty Images

Elena Rybakina, who lifted the Wimbledon title in 2022, is the highest-ranked player left in the women's singles draw and is playing some of her best tennis since she lifted the title.

The Kazkh world number four is bidding for a second Wimbledon final in three years but must find a way to overcome 31st seed Barbora Krejcikova in the next semi-final on Centre Court.

Despite arriving at SW19 with limited grass-court preparation, having retired from her second-round match at the Berlin Open with abdominal pain and then withdrawing from Eastbourne, Rybakina has excelled.

The 25-year-old took just 61 minutes to come through her quarter-final against Elina Svitolina and hit an impressive 28 winners.

Rybakina has only dropped one set at the All England Club this summer and has extended her record at Wimbledon to 19 wins from 21 matches.

Her win percentage of 90.5 is bettered only by Ann Jones and Steffi Graf in the Wimbledon women's singles in the Open era.

"I think that's an amazing statistic," Rybakina told BBC Sport.

"When I first played on grass I didn't feel comfortable, but my coach told me 'you were born for this, you just need to keep going'.'"