Vandeweghe doesn't have the best record against lefties - she's won five and lost 13 of her main draw matches against a left-hander.

Ooh. Back to back double faults from Vandeweghe offer Safarova a break point, but the American rescues it with a big serve that the Czech pushes wide.

Safarova misses a stroke down the line but Vandeweghe can't make hay as she slices her backhand into the net. Deuce number two.

Image source, Rex Features

Lucie Safarova's service game isn't as aggressive as Vandeweghe's, but she cracks down a fine ace to draw level at 30-30.

A rally goes the Czech's way, Vandeweghe blazing a forehand into the net, and Safarova holds.

And it's all over. Andrey Rublev finishes David Goffin off with a fierce return winner and will face Rafael Nadal in the last eight on Wednesday.

The Russian 19-year-old broke again to win 7-5 7-6 (7-5) 6-3.

Goffin appeared to have a knee injury issue during the match.

Image source, Reuters

Vandeweghe blasts through her opening service game, and she holds to love as Safarova flaps a forehand into the net.

Here we go. It'll be Vandweghe to serve first.

Image source, AFP

Russian teenager Andrey Rublev is on the brink of a US Open quarter-final against Rafael Nadal.

He leads Belgian ninth seed David Goffin 7-5 7-6 (7-5) 5-3 on Louis Armstrong Stadium.

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Vandeweghe won her first encounter with Safarova at Wimbledon in 2015, but since then the Czech has won all three of their matches.

This is Safarova's 13th consecutive appearance at Flushing Meadows but she's never gone beyond the round of four - in fact, this is her first round of 16 appearance since Wimbledon last year.

She's won 61 and lost 48 of her Slam matches and reached the final of the French Open two years ago, where she lost to Serena.

Image source, Getty Images

Vandeweghe is searching to make a big impression at the US Open for the first time since she was a teenager.

As a teenager, the New York native was given a wild card into the girls event at Flushing Meadows, where she tore through the competition to claim the title.

In the following eight years she failed to advance past the second round, and prior to this year had a 4-8 record at her hometown tournament.

Image source, Getty Images

Rublev currently has a 3-1 lead in the third set against Goffin...

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Cheers, Caz.

Big-hitting Coco Vandeweghe is into the round of 16 for the first time in nine main draw appearances at Flushing Meadows.

The world number 22 battled past 10th seed Agnieszka Radwanska in three sets to set up the meeting with Safarova.

Vandeweghe's best result at a Slam is when she reached the semi-finals at this year's Australian Open, where she was beaten by eventual finalist Venus Williams.

Image source, Getty Images

Fancy some Coco Safarova on a Monday evening?

No, it's not a fancy cocktail. It's the next fourth-round tie in the women's singles on Arthur Ashe Stadium.

Amy Lofthouse is going to guide you through it.

Rafael Nadal speaking after his 6-2 6-4 6-1 victory: "I think I played a solid match. I know he is a player who can play amazing shots but sometimes a little bit unpredictable. He combined amazing points with mistakes so I tried to be focused with myself.

"He was returning with a slice forehand I felt that, if I hit the forehand down the line, he has less space to attack.

"Carlos Moya, it is great to have him on the team. He's more than a coach. He's one of the best friends I ever had on the tour.

"I think he came with a lot of motivation and ideas and very positive all the time and believing a lot in what we're doing. A combination of him, Toni and Francis has been great."

Image source, Getty Images

Piers Newbery
BBC Sport at Flushing Meadows

A brutal forehand is swept into the open court and 19-year-old Andrey Rublev moves two sets up on eighth seed David Goffin, before asking the umpire, "Can I go to the bathroom, please?"

The teenager, who played a secondary-Challenger level event only three months ago, is on the verge of a Grand Slam quarter-final. Meanwhile, Goffin has heavy strapping on his knee and looks pretty forlorn.

Image source, EPA

Alexandr Dolgopolov waves to the crowd as he leaves the hard court, with an obvious look of dejection.

He pulled out some wonder shots at times, but it pretty one-sided on Arthur Ashe Stadium.

A fourth match point for Nadal now...but that's gone too! Rafa hits a wild return into the stands.

Three match points...gone!

Dolgopolov wins a brilliant rally by placing a backhand on the line.

To deuce.

Dolgopolov tries to plant a big forehand but it skews so high it ends up on Long Island.

Nadal brings up three match points.

Ace to start the game! No, wait. Dolgopolov challenges, and he's right. Kudos, my friend.

We go again, this time Dolgopolov's return goes long.

Nadal closes out his service game with a hold to 15.

The Ukrainian will serve to stay in the match.