Gigi Salmon
BBC Radio 5 live sports extra commentator at Flushing Meadows

Sevastova is fun to watch - if she's not happy, she lets you know it. When she's on it, and she's firing, she's a fearsome player. She dispatched Donna Vekic in the third round.

Image source, Getty Images

Sharapova's not capitalising on her break. She's landed a double fault and sliced into the net for 30-30.

A forehand winner settles her nerves but is outsmarted at the net by the tricky Sevastova and we go to deuce.

Sharapova takes her time to serve now, but she smacks into the net with a forehand to give the Latvian a break back point.

It's saved. We continue...

Russell Fuller
BBC tennis correspondent at Flushing Meadows

Sharapova has just strung together two commanding games. Some fantastic play, and it's a useful lead from her. Sevastova is showing, though, that she's not just going to go away or be bullied by Sharapova. Her defence was very sharp.

At 5ft 5ins, Sevastova is the kind of pocket rocket, tiny-but-mighty tennis player I like. She's quick, she's nimble, but she's super strong.

She goes on the defensive against an onslaught from the powerful Sharapova, but the Latvian messes up her drop shot and she hands her opponent the first break opportunity.

And Sharapova takes it with a backhand down the line, which Sevastova can't get back.

Image source, Getty Images

The crowd give the players a warm round of applause in appreciation for the first lengthy rally of the match. Sharapova slices and dices and finds a winner in the corner.

Spectators ooh and ahhh as they enter another battle, and the pair scamper around the court. Again, Sharapova nicks the point.

The Russian is 40-0 to the good and holds with a beautiful dinked effort which lands over the net with delicacy.

This is thoroughly entertaining already.

Maria Sharapova is going for the tramlines but her accuracy isn't on point at the moment.

Three separate errors give Anastasija Sevastova a 40-0 lead and the 16th seed finishes off with a smart drop shot.

Nice.

Image source, Getty Images

The unmistakable Sharapova grunt/screech comes out early doors, as she strolls into a 30-0 lead.

The Russian takes a deep intake of breath as she hits forehands outside the lines on two consecutive points.

A short, sharp 'c'mon' follows with a forehand cross-court winner for 40-30, before Sevastova cheekily volleys over from near the baseline for deuce.

Sharapova then takes the advantage and holds. The wildcard is off the mark.

Maria Sharapova earned a wildcard to this year's tournament as she continues to return from injury and her well-documented doping ban.

This is her 11th appearance at Flushing Meadows - and her first since 2014. Her best result came in 2006 when she beat Justine Henin to win the title - her second of five career Grand Slams.

A win today will see her reach the quarter-finals of a Slam for the 25th time.

Image source, Getty Images

Warm ups: done.

Quiet reflection in the chair: done.

Fluids supped: done.

Maria Sharapova, decked out in dusky pink, gets us under way in this fourth-round tie.

This is the first meeting between the pair.

Anastasija Sevastova is making her fifth main draw appearance at the US Open, and she achieved her best Grand Slam result of career at New York last year, when she reached the quarter-finals and lost to Caroline Wozniacki.

The 27-year-old hasn't dropped a set on her way to the last 16.

Image source, Getty Images

Here are the head-to-head stats coming into the US Open...

Image source, Getty Images

Poor Kyle Edmund looked heartbroken when he had withdraw with a neck strain against Denis Shapovalov in round three on Friday.

Our sympathy has diminished ever so slightly after seeing where the British number three has chosen to recuperate: paradise.

I cricked my neck at my friend's wedding last weekend. Where's my luxury holiday, eh?

Image source, Kyle Edmund facebook

Piers Newbery
BBC Sport at Flushing Meadows

Last night's torrential rain turned into drizzle this morning and now just a damp, autumnal chill. Organisers are confident enough to be opening the roof for Sharapova v Sevastova, however.

The dodgy weather doesn't seem to be putting off the fans, with a record crowd of 24,858 spectators hanging around for Roger Federer (and Feliciano Lopez) in the night session, which finished at 1.45am. Settle in, everyone.

Image source, BBC Sport

Roof news - it's opening as we speak! It's been closed for most of the day because of the poor weather in New York, but it looks like it's cleared for now over Flushing Meadows.

Follow latest scores from other courts here.

BBC Radio 5 live sports extra

BBC Radio 5 live sports extra are live now bringing you build-up and live commentary of Sevastova v Sharapova.

And here's the matches we'll be focusing on tonight on the live texts:

Image source, bbc

So, what's coming up today?

Maria Sharapova is next on the main court, as the world number 146 takes on sixteenth seed Anastasija Sevastova.

They're followed by new auntie Venus Williams, who plays Spain's Carla Suarez Navarro in the final day match.

Then it's two big names to kick off the night session, with Wimbledon champ Garbine Muguruza facing Petra Kvitova from midnight.

Then finally, home boy Sam Querrey takes on Mischa Zverev in the second men's match on Ashe.

Image source, Reuters

We have our first quarter-finalist!

Pablo Carreno Busta, the Spanish 12th seed in the men's draw, has beaten Canadian wonderkid Denis Shapovalov 7-6 (7-2) 7-6 (7-4) 7-6 (7-3).

He will now play the winner of Lucas Pouille and Diego Schwartzman.

Image source, Getty Images

Controversial? You could say that.

Back in form? Absolutely.

Maria Sharapova is aiming to reach the quarter-finals at Flushing Meadows for the first time since 2012.

Standing in her way is Latvian 16th seed Anastasija Sevastova. They will do battle next on Arthur Ashe Stadium.

Image source, Getty Images