Wildcard Sharapova beats world number two Halep 6-4 4-6 6-3 in 2hrs & 44mins
First Grand Slam match for Sharapova since 15-month ban
GB's Konta beaten 4-6 6-3 6-4 by world number 78 Krunic
Edmund beats 32nd seed Haase 6-3 7-5 6-3
Qualifier Norrie through after Tursunov retires when trailing 7-6 (9-7) 6-1
Watson loses 6-4 6-4 to Cornet; Venus, Muguruza & Kvitova through
David Law
Radio 5 live sports extra commentator at Flushing Meadows
The British media may be a tad deflated after Andy Murray's injury and Johanna Konta's defeat, but everyone's favourite US Open lift attendant, Tommy, is keeping spirits up...
Image source, BBC Sport*Sharapova 4-2 Halep
The crowd are right behind Sharapova here as she forces three break points.
She wastes the first two but breaks again on the third.
Third successive break of serve in the match.
Image source, AFPSharapova 3-2 Halep*
Sharapova's serve finally clicks into gear as she powers one down the centre to level at 30-30, having earlier double faulted in the game.
Anything short is getting dispatched by the Russian, but the unforced errors still creep into her game as Halep forces deuce.
The Romanian has another break point with an aggressive forehand and then counters Sharapova's drop shot, sending the Russian back pedalling with a volley to break back.
Jeff Tarango
Former professional tennis player on 5 live sports extra at Flushing Meadows
Sharapova is moving around the body serve really well. This match reminds me of the days when there were only 16 seeds. It's one of those matches where it's trouble for the higher seed because there is no pressure for the lower seed.
Image source, Getty Images*Sharapova 3-1 Halep
Halep is taken to deuce for the first time in the match. Sharapova is mixing her game up here, taking the pace off her returns with the odd drop shot and slice.
A first break point comes her way as Halep goes long after an 18 shot rally but the Romanian saves it with a big second serve.
Sharapova gets a second chance to break, finding the far corner with a return, but again Halep defends.
Both players battling early on here.
Third time lucky for the Russian? Nope.
Fourth time? Yes. Halep's second serve gets punished and put away.
Sharapova 2-1 Halep*
Huge relief for Sharapova, who saves her first break point but she has already made 10 unforced errors to Halep's two.
She had been 40-0 up, winning points with drop shots and strong ground strokes.
But Halep won the first major rally of the match, keeping Sharapova on the move and wrong footing her opponent with a forehand winner.
A double fault by the former champion and we're at deuce.
Sharapova saves a first break point with a forehand that just catches the line and eventually sees the game out after four deuces.
Image source, Getty Images*Sharapova 1-1 Halep
A drop shot from Sharapova brings in Halep to the net and the Russian then fires a backhand at the Romanian to leaving her sprawling and give her a 30-15 lead.
Sharapova nets as Halep gets back in front at 40-30 and finds the tape again as the world number two levels at 1-1.
Jeff Tarango
Former professional tennis player on 5 live sports extra at Flushing Meadows
A lot of murmurs around the crowd. It's just as much gossip as professional tennis - you can hear it. Three clean winners from Sharapova in the first game.
Piers Newbery
BBC Sport at Flushing Meadows
John McEnroe is alongside his brother Patrick working for the host broadcaster, and he poses some questions for Sharapova to answer: "I’m going to look at how well she moves, but that’s always a factor for her. The energy of the crowd will be a factor, will they be behind he or will they be on her? Because she had a ban for 15 months - I think she paid her dues - but let’s see."
Image source, BBC SportSharapova 1-0 Halep*
This is the first time Sharapova has faced a top 10 opponent since losing to Serena Williams in the 2016 Australian Open quarter-finals.
The left arm looks in good nick as the Russian scores with a fierce backhand winner.
Halep wins a couple of points but Sharapova finds her range in the last two points of the game to hold.
The players complete their warm-ups, Sharapova to start proceedings on a packed Arthur Ashe court.
Image source, Getty ImagesJeff Tarango
Former professional tennis player on 5 live sports extra at Flushing Meadows
Simona Halep is arguably playing the best tennis of her life. She is the world number two who could have become number one last weekend.
She's a retriever who will keep getting the ball back and keep making Sharapova hit another winner. That's where Maria's stamina will come into it.
She can hit one blaster but can she hit four or five in one point to beat one of the best player's in the world?
Both players have a quick word with the host broadcaster on the side of Ashe as they come out of the locker room. And to say they don't give much away is an understatement...
First up is Maria Sharapova, wearing a black dress studded with crystals: "It is a special night for me - it's been a while and I'm just excited about the opportunity. Every match at the beginning of the tournament, no matter what the head-to-head is, you take it as a challenge. That's what were both trying to do."
Then it is Simona Halep: "I know it was going to be a tough match so I'm ready and I have practiced well. I will enjoy this special night. I will try to do better than before against her and I will give everything."
Wondering why there has been a delay?
This was the pre-match show, they don't do things by half in New York.
Image source, Getty ImagesJeff Tarango
Former professional tennis player on 5 live sports extra at Flushing Meadows
I don't think Sharapova is as good a player now because I think she needed the stuff (meldonium) she was taking for her heart.
Not taking this prescribed drug she was banned for hurts her recovery and elasticity of her muscles. She does not look fit and does not look like she can last five three-set matches.
But playing one great match? That could happen. It could happen tonight.
Image source, maria sharapovaSharapova return has not exactly gone to plan.
She has only played in four tournaments and completed just 10 matches since April, winning six and losing four.
The five-time Grand Slam champion has struggled for fitness and is suffering from a left forearm injury which forced her to pull out of this week's Cincinnati Open.
She withdrew from the Stanford Bank of the West Classic earlier this month after suffering the injury in her first-round match.
The players are finally coming out on court.
Image source, Rex Features
Image source, Getty ImagesFormer champion Maria Sharapova is back at Flushing Meadows for the first time since 2014.
She missed the 2015 tournament with an injury and was banned for 2016.
But she is back this year and playing in her first Grand Slam since returning from a 15-month anti-doping suspension.
She was denied a wildcard to the French Open and missed Wimbledon qualifying with injury.
The world number 146 is in New York after receiving a wildcard from the United States Tennis Association.
Image source, ReutersIt's been a mixed day for the British contingent at Flushing Meadows.
The big upset of the day saw world number seven Johanna Konta suffer a shock first-round defeat against unseeded Serb Aleksandra Krunic.
Heather Watson is also out, losing to France's Alize Cornet.
The British men fared better, with Kyle Edmund and Cameron Norrie through to the second round.
Image source, ReutersShania's finished, she's not lost it. Thought I was back in 1999 then.
Now we have singer Jon Batiste performing the US national anthem.
I promise we have a tennis match coming up.