Pliskova has almost filled her sticker album of errors.

The latest lands wide.

0-15.

Williams then takes a turn. The American actually leads that race with 25-18.

15-15.

Jonathan Jurejko
BBC Sport at Flushing Meadows

Well. That Pliskova overhead into the net was greeted with a cheer louder than one after the winning goal in a Champions League final.

Cat Archer
BBC Radio 5 live sports extra on Arthur Ashe Stadium

You know the childhood friends of Juan Martin del Potro you hear chanting “Ole, ole, ole, ole, Del-po, Del-po?”

They’ve got a new member in the shape of Jeff Tarango.

Image source, Jeff Tarango

Do you smell a freshly-made bagel?

How on earth did Williams get to that and land it inside Pliskova's court?

And how did the Czech player fluff up that smash?

Big serve and it's 30-0.

Williams takes the first break point chance as Pliskova feeds the net once more.

It's like Pliskova has gone through a set doors and come out as a park player.

0-40.

Jonathan Jurejko
BBC Sport at Flushing Meadows

Blowing those two break points at 3-2 have proved mega costly for Pliskova. And she knows it.

Serena held and then went on to win the final four games. Serena's winners count soared to 19, while Pliskova's unforced error rate also went north to 14.

Can the Czech compartmentalise the disappointment and fight back?

40-0 as Pliskova smacks the ball into the net - if there was a competition for hitting the ball at the netting then...

Williams produces another double then goes wide in search for a slap-bang crosscourt winner.

Pliskova then goes long - we'll have a review though. Computer says, "it was long".

We go again.

Ace.

15-0.

Are we looking at bagel o'clock here?

Jeff Tarango
Former professional tennis player at Flushing Meadows

I keep thinking both players are looking stoic but then I realise it is the heat. Pliskova had to show more emotion. Once in the driver's seat she should have started fist pumping and being more animated to get herself pumped up.

She didn't really push herself to finish the set.

She takes it as Pliskova fires into the net.

Remember, Williams was 4-2 down in this set.

Pliskova fails to take advantage of her advantage.

Deuce.

And then finds the bottom of the tape once more.

A second set point.

Jonathan Jurejko
BBC Sport at Flushing Meadows

Cracking atmosphere inside Ashe now. The volume has ramped up in this game as Serena starts producing more hits than Dr Dre.

Boom!

Another one - the errors are turning into winners.

Set point.

WIlliams goes long with her return.

Deuce.

And then fires a forehand return narrowly wide.

40-15 as Pliskova fires the ball against the cord.

Williams defends then pounces with a forehand winner.

40-30.

Williams then sends a forehand on an express train to Coney Island.

It's deuce!

15-0.

Pliskova is holding her nerve so far.

The Czech then pulls out her doubles skills with a great lob volley.

30-0.

40-0.

This is gutsy from the world number eight.

Jonathan Jurejko
BBC Sport at Flushing Meadows

Pliskova has just started to move a few inches further back behind the baseline when Serena is serving.

Earlier her toes were placed in a long-jump perfect position on the white line.

She's won just two points in the past two Williams service games. She won 15 in the first three.

Williams picks out that wide serve again which Pliskova only just manages to get her racquet on - no direction though.

The six-time champ now has the lead.

15-15 as Williams brings up her 20th unforced error of the match so far.

She then sends down ace four.

30-15.

40-15.