Tracy Austin
Two-time Grand Slam champion on BBC TV

Iga Swiatek admitted after her first match that she's finding the grass difficult but she's working her way through it here.

Swiatek is smashing the ball all over the place and is no longer playing that badly, but Cornet is always there, always getting it back, always forcing one more shot... and sometimes finding a winner.

The top seed holds, eventually, but she has got her hands full here.

Incredible stuff by Cornet to somehow get a racquet on a Swiatek smash and send the ball looping back for the winner. Her defence is extraordinary, and it has helped her claw back to deuce here. More problems for the world number one.

Harry Poole
BBC Sport at Wimbledon

The pressure is on Iga Swiatek on Court One.

Alize Cornet smashes the ball away to take the first set and put the world number one’s ridiculous 37-match winning streak under threat.

Swiatek won’t be sweating just yet, there’s plenty of time to turn this around after all, but that was an impressive start from the world number 37. Can Cornet follow it up?

Swiatek only landed 53% of her first serves in that first set, and made 14 unforced errors, compared to five by Cornet.

The top seed needs to find her mojo, sharpish. She's gone for a bathroom break before the second set, but will she come back a different player?

The world number one is going to have to do this the hard way, otherwise that 37-game winning streak is toast.

Cornet puts away a smash to hold and take the first set. That's only the fourth set that Swiatek has dropped since March, and she's not lost a match since February.

The biggest upset of this year's Championships is on...

Image source, Gett

Two-time former champion Petra Kvitova digs in to hold her serve on Centre Court and leads Czech fourth seed Paula Badosa 4-2 in the first set.

• You can follow that match here

When it comes to her groundstrokes, Swiatek is not playing her best tennis but her serve has come to the party and she just blew Cornet away here.

Can Cornet keep her nerve now? She serves for the first set, next...

Cornet is wobbling a bit again at 30-all but every time she's in trouble, she seems to find a brilliant shot. She holds and is one game away from the first set.

Swiatek is still trying to overpower Cornet but the French player is giving as good as she gets, and is playing with the greater guile at the moment too - something she shows off to great effect with a stunning drop shot to settle an epic baseline rally and move to 15-all.

Tracy Austin
Two-time Grand Slam champion on BBC TV

Swiatek is starting to gain some momentum, starting to feel more comfortable. In that last point she didn't have to hit with so much pace, just good placement. That looked more like the right tempo.

At some point it will click for Swiatek and she will understand how she can build points.

Her forehand might be faltering but the Swiatek serve is working well now, however.

Cornet cannot get her next two deliveries back and sheer power wins Swiatek the next point too, to bring up another hold.

Tracy Austin thinks the Swiatek forehand doesn't work so well on grass because the way the ball slides through so quickly means she has less time for her big backswing, and that shot is still causing the Polish player plenty of problems as she slips to 15-30.

Swiatek steps it up even more here, firstly at 30-15 when she repeatedly forces Cornet so wide, that she's practically in a different postcode... and then to move to 30-40 with a big return and even bigger put-away volley.

Credit to Cornet, though, because she is not crumbling - she saved that break point, then out-foxed the Pole with some quick-thinking from the baseline and sealed the hold when Swiatek sent a forehand into the tramlines.

This first set has not changed direction yet...

Tracy Austin
Two-time Grand Slam champion on BBC TV

Alize Cornet's forehand is not quite as sturdy as her backhand. She's very accurate with the backhand, it's flat and it's penetrating.

No problems for Swiatek on serve this time. She's settled down after that dreadful start - although she is still a break down to Cornet.

On Centre Court, Czech fourth seed Paula Badosa has suffered an early break against two-time former champion Petra Kvitova.

• You can follow that match here

That's more like it from Swiatek... dealing brilliantly with Cornet's sliced backhand on deuce and then turning on the power to find the corners and break at the third time of asking. She's right back in this first set.

When Swiatek does land a shot, then she makes it count, and the Polish fans on Court One are quick to make themselves heard when it does.

She has got no consistency at the moment though. Another break point comes and goes when she fires a backhand horribly long.

Back to deuce. This feels like a big game for both players...

Lee Fergusson: "I think the win streak of Iga Swiatek might be coming to an end today."