Second Grand Slam of the season starts in secure bio-bubble at Flushing Meadows in New York
Kyle Edmund beats Kazakhstan's Alexander Bublik 2-6 7-5 7-5 6-0 in first round
Britain's Cameron Norrie comes from two sets down to beat Argentina's ninth seed Diego Schwartzman 3-6 4-6 6-2 6-1 7-5
American teenager Coco Gauff loses 6-3 5-7 6-4 to Anastasija Sevastova
Women's top seed Karolina Pliskova reaches second round; Petra Kvitova and Angelique Kerber also through
Novak Djokovic & Naomi Osaka play in the night session
Time to bring our coverage of Monday's play to a close, but you can follow Naomi Osaka's progress against fellow Japanese player Misaki Doi on our live scores page.
Here's a round-up of the key stories on day one of a US Open like we've never seen before...
Edmund 2-6 7-5 7-5 6-0 Bublik
Kyle Edmund joins fellow Brit Cameron Norrie in round two!
The British number two eases past Kazakhstan's Alexander Bublik in the end, winning 2-6 7-5 7-5 6-0 to set up a meeting with... Novak Djokovic.
Edmund, 25, faces a tough task to reach the third round of a Grand Slam for the first time in seven attempts, with 17-time Grand Slam champion Djokovic lying in wait in round two.
Serbia's world number one Djokovic, who has won all 24 of his matches in 2020, brushed aside Damir Dzumhur of Bosnia and Herzegovina in his opener.
Edmund 2-6 7-5 7-5 Bublik
Kyle Edmund has taken control now.
The British number two stumbles slightly as Alexander Bublik fights off three set points on his own serve but Edmund recovers to take his fourth opportunity.
Bublik produced three double faults as he tried to serve out at 5-4, too.
While the Kazakh lost his focus, Edmund kept his at the crucial moments and won three games on the bounce for a two sets to one lead.
Edmund 2-6 7-5 Bublik
That's more like it Kyle! Much better from British number two Edmund, who rounds off a good second set with a 96mph forehand winner.
Edmund looked in decent shape at the Battle of the Brits events after putting in the hard yards over the enforced break and will be hoping to kick on from here now against Bublik.
Since reaching the Australian Open semi-finals in 2017, the 25-year-old Yorkshireman has not ventured past the third round of a major.
Could he break that less-than-satisfying run at Flushing Meadows?
Edmund 2-6 Bublik
Alexander Bublik is ranked 10 places below Kyle Edmund, but is one of those players with who you never quite know what is going to happen. Unorthodox, shall we say.
He's played out of skin here. Fifteen winners from the Kazakh's racquet and just four unforced errors.
Bublik serves and volleys on break point as he tries to close out the first set, the tactic coming up trumps as he serves out to clinch the first set in little over half an hour.
Edmund v Bublik
Let's hope for the sake of you British fans heading back to work in the morning that Kyle Edmund doesn't need so long to win tonight.
The British number two, now ranked 44th in the world, has just started what is likely to be a tough match against Kazakhstan's Alexander Bublik.
And here is a potentially bad omen... Edmund's last match at the US Open was a five-set marathon.
Click the audio tab to listen to 5 Live Sports Extra radio coverage.
Image source, EPABad news for Coco Gauff fans (and US Open organisers)... the American teenage phenomenon is out.
A tough afternoon for the 16-year-old who struggled with her service game in a 6-3 5-7 6-4 defeat by Latvian 31st seed Anastasija Sevastova.
Sevastova is quite the Flushing Meadows specialist having reached the quarter-finals in 2016 and 2017, then going one better to the last four in 2018.
Image source, EPALet's have a catch-up around the courts at Flushing Meadows...
Top seed Karolina Pliskova has made a confident start to her US Open campaign with a 6-4 6-0 win over Ukraine's Anhelina Kalinina.
The Czech, 28, recovered from dropping serve in the first game to later string together eight games in a row, needing just 21 minutes to take the second set.
Pliskova, top-ranked in the absence of Ashleigh Barty and Simona Halep, faces France's Caroline Garcia next.
Also through are two-time Wimbledon champion Petra Kvitova and 2016 US Open champion Angelique Kerber.
German 17th seed Kerber, playing her first match since January's Australian Open, beat Australian Ajla Tomljanovic 6-4 6-4.
Czech sixth seed Kvitova overcame Romanian Irina-Camelia Begu 6-3 6-2, hitting 23 winners in an assured performance.
Image source, EPAThat's all from us, we're going to catch our breath after that epic.
Later, Kyle Edmund plays his first-round match against Kazakhstan's Alexander Bublik... although that might be pretty late after Norrie's epic.
Novak Djokovic, Coco Gauff and Naomi Osaka are all in action later too so we're in for quite a night.
In the meantime, you can catch up on Norrie's win by reading Jonathan Jurejko's report here.
And you can carry on listening to BBC radio commentary of the day's action by clicking on the link at the top of this page.
There's been plenty going on around the Billie Jean King tennis centre while Norrie and Schwartzman were engaged in that epic.
Top seed Karolina Pliskova made a confident start with a 6-4 6-0 win over Ukraine's Anhelina Kalinina.
Pliskova, top-ranked in the absence of Ashleigh Barty and Simona Halep, faces France's Caroline Garcia next.
Also through are ex-Wimbledon champions Petra Kvitova and Angelique Kerber.
Read more here.
Image source, Getty ImagesSchwartzman 6-3 6-4 2-6 1-6 5-7 Norrie
More from Cameron Norrie on Amazon Prime:
"I thought I'd play and hit the ball down the middle for a couple of games and get some rhythm. I kept the momentum going and kept building.
"I backed myself physically. He was struggling a bit at the end. Schwarzman was getting upset at some of the British guys cheering. That helped a lot."
Schwartzman 6-3 6-4 2-6 1-6 5-7 Norrie
Cameron Norrie said on Amazon Prime:
"I'm pretty tired actually. The tennis and the level wasn't that great but I had a good attitude throughout and I was happy with that.
"I'm lucky to get through that one. It was a tough one.
"In the first couple of sets, there were so many second-serve returns when I had break points and I was getting frustrated. I managed to convert way more at the end.
"The first two sets I was rushing everything and going for too much. I was making way too many errors."
Schwartzman 6-3 6-4 2-6 1-6 5-7 Norrie
Norrie has made it to the second round of the US Open twice before: in 2017 and 2018.
He's never made it to the third round though...
Schwartzman 6-3 6-4 2-6 1-6 5-7 Norrie
Norrie faces another Argentine opponent in the second round: Federico Coria.
If he can recover from that four-hour epic, it could be a bit more straightforward. Coria is ranked 27 places below Norrie at 103rd in the world.
Judy Murray
Tennis coach on BBC Radio 5 Live Sports Extra
That is a great win for Norrie and he looked strong right to the end. Schwartzman really started to struggle with cramp and he was really unable to test Cam in the end. When you're cramping it's so tough in your head as you know you're not going to be able to run around.
Schwartzman 6-3 6-4 2-6 1-6 5-7 Norrie
He might not care, but you almost have to feel a bit sorry for Cam Norrie. That's such an incredible victory and there are no fans there to celebrate.
It's all a bit anticlimactic as he packs away his things in silence and prepares to leave the court. There wasn't even much of a celebration, just a halfhearted fist pump.
Schwartzman 6-3 6-4 2-6 1-6 5-7 Norrie
He's done it!
Absolutely incredible. Schwartzman hits a forehand into the net and Norrie has come back from two sets down to knock out the ninth seed.
*Schwartzman 6-3 6-4 2-6 1-6 5-6 Norrie
Schwartzman sends Norrie right, then smashes a forehand winner left. Second match point saved.
*Schwartzman 6-3 6-4 2-6 1-6 5-6 Norrie
Wow! Schwartzman looks to have hit the ball long but it just drops right on the line and Norrie can't believe it.
One match point saved.
*Schwartzman 6-3 6-4 2-6 1-6 5-6 Norrie
While Schwartzman is seemingly glued to the ground, Norrie is bouncing at the other end of the court.
He has three match points.