Jeff Tarango
Former professional tennis player on BBC Radio 5 live sports extra

Serena is a stride ahead. She is front-running and stringing out. Her pace has picked up by 15-20%. The second serve percentage returns from Sevastova - in the low 70s - is just not enough.

But there's no stopping Serena this time! She's at the net yet again. It's like this match is being played on a 90s grass court. She waves a fist to her box after smashing away another winner. Williams has won seven of the last eight games. She leads by a set and a break.

Ooooof. This is a big call.

On the final break point Serena goes for a passing shot and Sevastova leaves it at the net. It flashes past her and bounces near the baseline. Was it in or was it out?

Hawk-Eye is being called for again. It's out! Three break points saved.

Williams now has three break points. She looks disgusted after hitting into the net on the first.

Two more to come...

Double fault from Sevastova to start the second set.

Any Latvians reading this? It might be time to panic.

Jeff Tarango
Former professional tennis player on BBC Radio 5 live sports extra

Serena's power is just overwhelming!

David Law
BBC Radio 5 live sports extra commentator at Flushing Meadows

Serena has worked out that an all-out net attack is the best way to deal with an all slice-and-dice game from Sevastova. It is hard to imagine what Sevastova can do to change things here.

Image source, Getty Images

Into the net again comes Williams and Sevastova goes wide. After a slow start, that was dominant from Serena.

A tough job has just got a whole lot tougher.

And another ace. Sevastova challenges but it clipped the line. Could have been placed better by hand.

Two sets points to Williams.

Williams now serving for the first set...

A huge 120mph ace to start.

15-0.

Jonathan Jurejko
BBC Sport at Flushing Meadows

"Good shot!' shouts one fan near the media seats as Serena lined up that winning smash.

He called it. As soon as the ball bounds off to safety, both husband Alexis and coach Patrick Mouratoglou jump to their feet with right clenched fists.

Wonder who Serena makes eye contact with first...

Sevastova is now on the same side of the court as her box. She wins a point and is still chirping away in her coach's direction. I'm not sure what she's complaining about but having watched her previous game I think she just likes to rant.

The Latvian stops the run of five games in a row for Williams and then stretches out her hamstrings.

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

Bad traffic getting to Queens tonight so our commentator David Law got a special escort to Flushing Meadows.

(THIS POST IS NOT SERIOUS)

Image source, David Law

Serena is clenching her fist now. There's not much Sevastova can do at the minute. I fear if Williams keeps this level up then the Latvian loses comfortably. Sevastova looks worriedly over to her box on the way to her chair.

Jonathan Jurejko
BBC Sport at Flushing Meadows

Spidercam is a bit of nuisance here. The suspended camera hovers over the court at the changeover, and crept towards Sevastova to look her in the eye before retreating in its hole behind the baseline.

The Latvian was forced to wait to start that service game and her steely glare indicated she wasn't too happy.

Not saying that had an effect, but...

David Law
BBC Radio 5 live sports extra commentator at Flushing Meadows

Serena is showing a new dynamic to her game right now. We all know she can do it - she has won doubles titles with her sister. But she is at the net more tonight than I have ever seen her. Four games in a row. She is flying!

Bang. That's big. Serena slaps the ball away cross court. It was passed Sevastova before she had even finished her swing on the previous shot.

Irresistible from Williams. Four games in a row. Another break.

Sevastova is chuntering away and waving her arms. She looks distressed. It's no wonder. Serena is charging into the net and smashing the ball away.

Here's another break point for the American.

The rain is now belting down on the roof of Arthur Ashe Stadium. It's like the players are playing in a greenhouse or inside a tent on a stormy day in the Lake District.

Sevastova was brilliant in the opening two games, taking an early 2-0 lead, but she's now lost three games in a row.

This is an important game for her. We're at deuce.

Image source, Getty Images

There haven't been any outbursts of emotion yet from Serena, no big fist pumps or screams of come on. She looks calm.

The American hits a stunning backhand passing shot to take this latest game leaving Sevastova stranded in the middle of the court.

Sevastova is a player who often shows negative emotions on court. Her eyes seem to be getting wider and wider and a little more panicked.