Jess Anderson
BBC Sport at Wimbledon

And with that, the roof is coming on over Centre Court.

Just like last night with Andy Murray's match the roof was closed following the previous match, even though there's probably a bit more light left in the day.

No chances are being taken and with an electric atmosphere created under the lights last night organisers will hope for something similar as Novak Djokovic takes on Stan Wawrinka next.

Let's hear from world number one Iga Swiatek:

"It wasn't easy, Petra was playing well and I was focused from the beginning to the end and it gave me confidence I could close it in the second set.

"I'm glad I am doing well on grass and that's important for me."

On her grass-court form:

"There's always something we want to improve. It's impossible to play perfectly. I feel like I have a lot to learn and it gives me hope I will get better and better every year, and it's a motivation."

"I didn't know I was going to play against Belinda. She is playing a great game and we all know she can play great tennis.

"I'm really looking forward to that match."

Michael Emons
BBC Sport at Wimbledon

Image source, BBC Sport

Happy couple Alex de Minaur and Katie Boulter, boyfriend and girlfriend and playing as a pair in the mixed doubles, have just had a date to remember.

They have won in the first round against Australians John Peers and Storm Hunter, by a 6-2 6-4 scoreline.

De Minaur and Boulter looked like they enjoyed every second of the experience, with high fives at every game and with them regularly laughing, smiling and joking at each handover before giving each other a warm hug at the end. Lovely.

Image source, BBC Sport

Right then, a Friday night treat as defending champion Novak Djokovic takes on Stan Wawrinka in the final Centre Court match.

Djokovic has labelled the meeting with his old rival as "the duel of the veterans of the tour". Three-time Grand Slam winner Wawrinka, 38, has twice beaten Djokovic in Grand Slam finals but says he "doesn't really stand a chance".

Djokovic, 36, clinched his 23rd major at the French Open last month, but lost to Wawrinka in the 2015 French Open final and the 2016 US Open final.

Asked what role 88th-ranked Wawrinka has played in his career, Djokovic joked: "Well, he took away two Grand Slams from me.

"No, I like Stan a lot. He's a great person and really inspirational what he's doing at his age. He's almost 40 and he still keeps going strong, that's something not many people can do.

"He's had a fantastic career. We haven't faced in quite some time. It will be the duel of the veterans of the tour."

Image source, Getty Images

Tracy Austin
Two-time Grand Slam champion on BBC TV

I think Iga will be pleased with the way she played and against a crafty opponent who tried everything.

I don't think it's bad that she got tested.

It's good for her.

Jess Anderson
BBC Sport at Wimbledon

She got there in the end!

Just that one game that was a bit of a blip for Swiatek but she's got the job done here, much to the delight of the Centre Court crowd.

She kept them waiting at the end, mind.

Three match points brought up for Iga Swiatek.

The first is a strong serve but Petra Martic brings her forward and her attempted passing shot hits the net.

The second? She goes long!

Pressure.

Bosh, that's more like it from Iga Swiatek.

She went missing for a game and a half but from 40-0 down on Petra Martic's serve, an incredible backhand winner sets up deuce.

It's followed up with another that wrongfoots Martic and brings up an immediate break-back point.

Which she seals! All that hard work from Martic - and Swiatek has another chance to serve for the match.

Jess Anderson
BBC Sport at Wimbledon

Martic goes for the drop shot then sends Swiatek sprinting to the back of the court. The Pole gets there but can only manage to hit the backhand high into the sky above Centre Court and it drops on the wrong side of the baseline.

Should've gone for the tweener there, Iga.

Michael Emons
BBC Sport at Wimbledon

Image source, BBC Sport

Alex de Minaur and Katie Boulter, boyfriend and girlfriend, are partners in the mixed doubles and in the second set of their round-one opener against Australian duo John Peers and Storm Hunter.

De Minaur lost today in the men's singles second round, while Boulter plays world number three Elena Rybakina of Kazhakstan in the women’s third round tomorrow.

De Minaur has been full of praise for Boulter and earlier today said this in his news conference following his loss to Italy's Matteo Berrettini:

"Since the moment I met her I knew she had it in her, I've always thought she's such a high-quality player," said De Minaur.

"It's been amazing and great to see how she's developed. She's got that self-belief and what she's been able to accomplish. I mean, the way she's been handling the spotlight, the pressures, it's been pretty astounding to me. You know, now it's probably my turn to start learning from her.

"But yeah, she's been playing amazing. She's been doing amazing. She's shown again this week that she deserves to be where she's at, and I think, genuinely think, that it's only the beginning. Hopefully she can keep on going and finish off a great year."

It’s all going well on the court, with the couple a set up and on serve in the second.

Image source, BBC Sport

Tracy Austin
Two-time Grand Slam champion on BBC TV

That is surprising. A very uncharacteristic game from Iga Swiatek.

Jess Anderson
BBC Sport at Wimbledon

Woah, let's not speak too soon folks.

Image source, Getty Images

Backhand. Cross-court. No! Iga Swiatek goes long and it's three break points for Petra Martic.

I thought this match was all but done but suddenly we're back on serve as Swiatek fires an uncharacteristic forehand into the net.

The Centre Court crowd are suddenly weighing up a longer match here.

Here's what Elina Svitolina, who only made her return to tennis in May after giving birth in October, told BBC TV after her win over Sofia Kenin: “It was good to win the first set, it was really close. I was happy I could bounce back after being a break down. The shadow from the sun was tough so I was happy I could win first and I was then playing more freely in the second."

On what’s clicking for her at Wimbledon: “I’m just enjoying it. I appreciate every moment on the court because I was not playing for one year. Being at home it was an unbelievable moment for me and Gael [Monfils] to have our daughter but I was really looking forward to coming back to the court and to play such an event like Wimbledon. The Grand Slams are a big motivation for me and I’m appreciate every moment."

The Ukrainian jokes that it's her husband Gael Monfils' turn to look after their daughter as she continues her Wimbledon run.

Image source, Getty Images

Well, well, Petra Martic is mounting some resistance here.

A well-executed point, complete with unorthodox volley, brings up 0-30 and Iga Swiatek needs a response if she's not to be broken back.

Tracy Austin
Two-time Grand Slam champion on BBC TV

I think Swiatek is starting to feel more confident.

Before Roland Garros, there are six weeks to play on clay.

The grass-court season is just three weeks and after Roland Garros people need a rest, so most people only play a couple of tournaments on it.

Each week you play on grass you feel more comfortable.

Jess Anderson
BBC Sport at Wimbledon

Prolonged just a bit longer and Martic will be pleased to have not given it away as we seem to have got to this point quite quickly.

The top seed will have to serve it out. Unless there's another twist?

Iga Swiatek will have to serve for it.

Petra Martic digs deep to force deuce on her serve before clubbing a forehand that has Swiatek skewing off target.

A big serve later and Swiatek's reply goes into the net.

Jess Anderson
BBC Sport at Wimbledon

This has been comfortable really for Swiatek.

Martic has kicked it up a notch in the second set but the Pole has still found a way and is now looking at a third straight-sets victory this week.