Man UtdManchester United1ArsenalArsenal2
Arsenal beat Man Utd in FA Cup - as it happened
Got a TV Licence?
Find out moreSummary
- Arsenal through to semi-finals
- Welbeck scores winner against old club
- Di Maria sent off after grabbing referee
- Semi-final draw: Bradford/Reading v Arsenal; Aston Villa v Liverpool/Blackburn
Live Reporting
Tom Rostance
All times stated are UK
Get involved
EPACopyright: EPA Getty ImagesCopyright: Getty Images ReutersCopyright: Reuters Getty ImagesCopyright: Getty Images @HectorBellerinCopyright: @HectorBellerin ReutersCopyright: Reuters APCopyright: AP PACopyright: PA cruserCopyright: cruser BBC SportCopyright: BBC Sport ReutersCopyright: Reuters Getty ImagesCopyright: Getty Images BBCCopyright: BBC ReutersCopyright: Reuters ReutersCopyright: Reuters APCopyright: AP Getty ImagesCopyright: Getty Images PACopyright: PA APCopyright: AP ReutersCopyright: Reuters Getty ImagesCopyright: Getty Images Getty ImagesCopyright: Getty Images BBCCopyright: BBC Getty ImagesCopyright: Getty Images ReutersCopyright: Reuters Getty ImagesCopyright: Getty Images ReutersCopyright: Reuters APCopyright: AP EPACopyright: EPA Getty ImagesCopyright: Getty Images Getty ImagesCopyright: Getty Images PACopyright: PA APCopyright: AP ReutersCopyright: Reuters APCopyright: AP Getty ImagesCopyright: Getty Images Getty ImagesCopyright: Getty Images Getty ImagesCopyright: Getty Images Getty ImagesCopyright: Getty Images Getty ImagesCopyright: Getty Images Getty ImagesCopyright: Getty Images Getty ImagesCopyright: Getty Images BBCCopyright: BBC APCopyright: AP BBCCopyright: BBC Getty ImagesCopyright: Getty Images BBC SportCopyright: BBC Sport Getty ImagesCopyright: Getty Images BBC SportCopyright: BBC Sport BBC SportCopyright: BBC Sport Getty ImagesCopyright: Getty Images BBCCopyright: BBC ReutersCopyright: Reuters Getty ImagesCopyright: Getty Images Getty ImagesCopyright: Getty Images Getty ImagesCopyright: Getty Images EPACopyright: EPA Getty ImagesCopyright: Getty Images PACopyright: PA Getty ImagesCopyright: Getty Images
Latest PostPost update
That's all from us for the night - catch up with all of the reaction, highlights and interviews on our FA Cup index. And we shall see you tomorrow for the Champions League.
Post update
As if Danny Welbeck scoring at Old Trafford wasn't bad enough for Manchester United fans, another one that got away has been at it too.
Paul Pogba produced a stunning winner to increase Juventus's lead over Roma at the top of Serie A to 11 points with victory over Sassuolo.
The former Manchester United midfielder fired the ball home from outside of the box as Juve finally broke through Sassuolo's defence in the 82nd minute.
Post update
A reminder that you voted Arsenal midfielder Francis Coquelin as man of the match tonight, the Frenchman won 43.2% of the vote.
Post update
Man Utd 1-2 Arsenal
Phil Neville
BBC Radio 5 live
"Reading between the lines there, Louis van Gaal sounds like he's really angry with Di Maria. You cannot put your hands on the referee like he did."
Post update
Man Utd 1-2 Arsenal
Martin Keown
BBC Sport on BBC Radio 5 live
"I think he's been an accident waiting to happen Angel Di Maria in the last few weeks. But, how much help has Di Maria had? The manager has picked him, but what kind of support has he had from everyone around the club to look out for him?"
Post update
Man Utd 1-2 Arsenal
Phil Neville
BBC Radio 5 live
"Momentum works both ways and for United now, they can't win silverware and all they've got left to concentrate on for the rest of the season is a top four finish.
"There's tricky period for them when they still have to play the likes of Chelsea, Man City, as well as Everton.
"It's a massive. massive last two months of the season for them. The results have been OK, but the performances have got to improve."
Post update
Man Utd 1-2 Arsenal
A stat from Opta here which takes us back to a point we made earlier in the evening:
8 - Only Adebayo Akinfenwa (9 v Liverpool) has conceded more fouls in a 2014-15 FA Cup match than Marouane Fellaini v Arsenal.
Player reaction
Man Utd 1-2 Arsenal
BBC Radio 5 live
Arsenal captain Per Mertesacker: "In the second half there was a feeling we could get something out of it. The crowd got nervous, we were rewarded with the second goal and then we defended from the top in a special way.
"Danny Welbeck was a great player here at United, he's a bit quiet in the dressing room at the moment. I think it hurts him a bit as well as he was here for a long time. We tried to get him going and to tell him he can enjoy special moments with Arsenal."
Manager reaction
Man Utd 1-2 Arsenal
Manchester United boss Louis van Gaal: "I've said in the dressing room we gave [the game] away by ourselves and that is the biggest disappointment. In the second half, we had the first chance also then we gave it away again.
"We don't lose from the opponent, we lost from ourselves and it was very disappointing. You play this match to win; to beat the opponent, we wanted to be in the semi-final."
Post update
Man Utd 1-2 Arsenal
Martin Keown
BBC Sport on BBC Radio 5 live
"When you have performances like this, as Arsenal you look back and see it as a defining moment. I think the aura of Old Trafford has slipped away now.
"They've lost nine games here in the last two seasons and under Alex Ferguson, that was six seasons worth of defeats."
Manager reaction
Man Utd 1-2 Arsenal
Manchester United boss Louis van Gaal: "I said in advance that [the top four] is a priority but as a manager, and as a player and club you want to win titles and now we cannot win a title."
Post update
Man Utd 1-2 Arsenal
The build-up - if you can call it that - to Arsenal's winner is so poor from Manchester United's point of view. Just a goal-kick downfield. Phil Jones fluffs his chest down under minimal pressure, Antonio Valencia gives the ball away under minimal pressure and Danny Welbeck nips in to score.
Post update
Man Utd 1-2 Arsenal
Martin Keown
BBC Sport on BBC Radio 5 live
"Fair play to Danny Welbeck. He was prepared to celebrate. He was born and bred United, but he's changed colours now and he was determined not to see his former team-mates walk out at Wembley in a May final."
Join the debate at #bbcfacup
Arsenal's Hector Bellerin is quick off the mark with a post-match selfie: So happy to get to the semi-final of the FA Cup and for Nacho. WEMBLEY!!! #COYG
Join the debate at #bbcfacup
Okey Francis: Welbeck and Paul Pogba saviours of their respective teams tonight. Wish it were Man Utd..bundles of talent we let go.
Owen Davies: So last train to Euston left on 70 mins. There'll be a few Utd supporters left stranded in Manchester tonight
'Touching the ref is forbidden'
Man Utd 1-2 Arsenal
Manchester United boss Louis van Gaal on Angel Di Maria's sending off: "In Spain he knows that he doesn't touch the referee, but that is also in his emotion. I've already spoken with him, he knows my opinion but also I have to see on the video.
"I think he's touched the referee and that's forbidden in every country, so he has no excuses."
5 live Football Social
BBC Radio 5 live
Martin Keown and Phil Neville will be joining Kelly Cates after the news where you've got until 22:30 GMT to get your calls in to have your say.
Lines are open - Call 0500 909 693, text 85058 or tweet @bbc5live
Join the debate at #bbcfacup
Cameron Johnson: Reading v Arsenal semi would be good. Last 3 meetings between teams has provided 24 goals including their last cup match at 7-5.
Post update
Man Utd 1-2 Arsenal
When Manchester United manager Louis van Gaal is asked if there are elements of the performance which are positives, he just laughs.
Full reaction to come...
Post update
Man Utd 1-2 Arsenal
Danny Welbeck says he never imagined scoring a winning goal against Manchester United. I don't suppose many United fans did either...
Post update
Man Utd 1-2 Arsenal
Phil Neville
Match of the Day, BBC Sport
"I think United lost the game in midfield. Arsenal were too quick for them in there. Daley Blind really struggled and Welbeck sat deep to protect Arsenal when they didn't have the ball."
Post update
Man Utd 1-2 Arsenal
Roy Keane
Match of the Day, BBC Sport
"I think David De Gea's the best goalkeeper in the world at the moment. But for United, it's not a good sign at the moment when he's getting man of the match most weeks."
Women's Cup Final
Some landmark news to announce too, The FA Women's Cup final 2015 will be played at Wembley Stadium this year for the first time. It will be held on 1 August 2015 and the BBC will bring it all to you live.
Post update
Man Utd 1-2 Arsenal
That last-minute save from David De Gea to deny Alexis Sanchez was absolutely sensational.
Post update
Man Utd 1-2 Arsenal
Roy Keane
Match of the Day, BBC Sport
"Louis van Gaal's going to be criticised after the game, but you've got to give him a chance.
"It takes time, he's only been in the door five minutes.
"A lot of fans don't understand the game and how much of a challenge it is to run a club the size of Man United. They should've given David Moyes more time, but they didn't."
Join the debate at #bbcfacup
Neal Collins: Certainly looks like an @Arsenal v @LFC final, remember Charlie George, 1971? I named my first dog after him!
Joe Davies: Looks like #Gerrard's dream career ending is still on then. Looking like #Liverpool v #Arsenal for the #FACup final at #Wembley.
Manager reaction
Man Utd 1-2 Arsenal
Arsenal manager Arsene Wenger: "Last year we played a tricky game at Wembley in the semi-final and we expect that again. Tonight I thought we played well and deserved to win the game.
"We had to start without apprehension and play at a a high pace and we did that well. Danny Welbeck, I believe is just happy to score. He worked extremely hard today and deserved his goal.
"We live in the real world and want to compete in every competition. This result can give us good morale for the Premier League and the game in Monaco."
Post update
Arsenal will fancy their chances against either Reading or Bradford City at Wembley - but don't forget that Bradford knocked Arsenal out of the League Cup just two years ago.
Join the debate at #bbcfacup
Liz Tray: Poor United. Without De Gea it'd have been worse. My heart bleeds for them and their 20 titles. Still, there's always the Europa League?
Victor Chatfield: Lots of decisions went Arsenal's way. Adnan Januzaj lost his balance and didn't seem to appeal. No foul, but no dive either. Lucky Arsenal.
From draw to dance floor
Fresh from helping conduct this evening's draw, Dermot O'Leary is dancing non-stop for 24 hours on Thursday to raise money for Red Nose Day 2015.
He's be live from the piazza at BBC's New Broadcasting House and dance live all the way into London's Palladium where the night of Red Nose Day TV is being filmed.
He needs the public to sponsor him by texting DERMOT to 70005 to donate £5 (cost £5 plus standard network rate) or by visiting the Red Nose day website.
You can follow the action live on BBC Radio 2 and on the BBC Red Button.
Post update
Man Utd 1-2 Arsenal
Roy Keane
Match of the Day, BBC Sport
"I think it's important to celebrate the goal for Danny Welbeck. Yes, he's a local boy, but he's got to do his best for Arsenal."
Join the debate at #bbcfacup
David Lee Starr: Man Utd players let us down. Took a sending off to show some spirit. Not good enough
Mic Medeska: United supporter here. Michael Oliver was spot on perfect today. No complaints there.
Luke: De Gea is going to get fed up with saving United week in week out. Ronaldo got fed up. Real Madrid in the summer is odds on.
Post update
Happy with that Arsenal fans?
The FA Cup draw
Aston Villa v Liverpool or Blackburn Rovers
The FA Cup draw
Bradford City or Reading v Arsenal
The FA Cup draw
Here comes the draw with ex-United keeper Peter Schmeichel and presenter Dermot O'Leary picking the balls.
The numbers to look out for will be:
1 Liverpool or Blackburn Rovers
2 Bradford City or Reading
3 Arsenal
4 Aston Villa
The semi-final ties are to be played on 18 and 19 April.
Post update
Man Utd 1-2 Arsenal
Roy Keane
Match of the Day, BBC Sport
"Shocking defending for the second goal. Phil Jones had time to clear, he can do better, the goalkeeper could've sacrificed himself there and Danny Welbeck had read the poor back pass."
Post update
Man Utd 1-2 Arsenal
Ian Wright on Match of the Day
BBC Sport
"Danny Welbeck was in the right place for Antonio Valencia's mistake, but Arsenal didn't have much to do. I don't think Manchester United had too many ideas. It was a lot easier for Arsenal than they would have expected."
Post update
The BBC pundits are all in agreement that Danny Welbeck should have celebrated his goal. That's a trend we need to see come back isn't it?
Post update
Man Utd 1-2 Arsenal
Phil Neville
BBC Radio 5 live
"It was a brilliant performance from Arsenal, such speed in the counter-attacks and United couldn't cope with the speed in those midfield interchanges. Arsenal would've had two or three goals in that second-half had it not been for David De Gea."
Post update
Man Utd 1-2 Arsenal
Roy Keane
Match of the Day, BBC Sport
"The shocking defending meant Arsenal made the most of it. You couldn't begrudge Arsenal that win, they thoroughly deserved it."
In the hat
Draw coming up
BBC One
Don't forget we'll shortly bring you the draw for the FA Cup semi-finals live on BBC One.
Former Man United keeper Peter Schmeichel and Arsenal fan Dermot O'Leary will draw the all important numbers for the Wembley ties in April.
5 live Football Social
BBC Radio 5 live
Lines are now open for you to keep the debate and reaction going after full time tonight with your calls and social media reaction on the BBC Radio 5 live Football Social from 21:45 GMT.
Call 0500 909 693, text 85058 or tweet @bbc5live to have your say.
FULL-TIME
Man Utd 1-2 Arsenal
Arsenal have done it. Danny Welbeck's goal is enough for Arsenal to knock out his old club!
Post update
Man Utd 1-2 Arsenal
United pump it long- out of play...
Post update
Man Utd 1-2 Arsenal
Phil Neville
BBC Radio 5 live
"Brilliant counter-attack from Arsenal, brilliant speed and that's another world class save from David De Gea."
GREAT SAVE!
Man Utd 1-2 Arsenal
It's another brilliant save from David De Gea but Arsenal should score! Mesut Ozil passes to Alexis Sanchez when the shot was on and Sanchez's low drive is somehow tipped away. Phenomenal stop!
Text us on 81111
Man Utd 1-2 Arsenal
Marc from London: "Good to see cheating being punished for once."
Post update
Man Utd 1-2 Arsenal
Phil Neville
BBC Radio 5 live
"Arsene Wenger is giving a message to Francis Coquelin to sit in front of Marouane Fellaini to give a screen to protect those balls up to the top from United."
Post update
Man Utd 1-2 Arsenal
Chris Smalling almost ferrets a way through into the box but Per Mertesacker hammers it clear...
Text us on 81111
Man Utd 1-2 Arsenal
Craig Barber, North London: "Michael Oliver is my man of the match."
Post update
Man Utd 1-2 Arsenal
John Murray
BBC Radio 5 live commentator
"Arsene Wenger turns away in disgust after seeing that five on the board and then shakes his head."
INJURY TIME
Man Utd 1-2 Arsenal
FIVE MINUTES added on. For 95% of my life I would have expected a late Manchester United goal in this situation, but I'm not so sure now. Arsenal are keeping the ball nicely and killing the clock.
Join the debate at #bbcfacup
James Taylor: Hang your head in shame Adnan Januzaj. Referee earning his pay tonight.
Jack McLeod: Looks like this United side are planning to take up a new sport this summer. Tom Daley has competition.
Post update
Man Utd 1-2 Arsenal
That's seven bookings for Manchester United which will bring a fine from the Football Association. Can they stay in the FA Cup?
Man of the match vote
So, who do you think has made the difference tonight?
You can vote for your FA man of the match on the right-hand side of the page or via the vote tab on your mobile or tablet. Full terms and conditions here.
YELLOW CARD
Man Utd 1-2 Arsenal
Aaron Ramsey now booked, that's nine bookings in the game...
Post update
Man Utd 1-2 Arsenal
Danny Murphy
BBC One
"That was the right decision and a brave decision by the referee right in front of the Stretford End."
Post update
Man Utd 1-2 Arsenal
Phil Neville
BBC Radio 5 live
"Adnan Januzaj showed brilliant ability on that right-hand side to go past Nacho Monreal, but it's a brilliant decision, there was no need to go over. There was no contact at all and Januzaj goes down too easily."
PENALTY APPEAL
Man Utd 1-2 Arsenal
Referee Michael Oliver in the game again as Adnan Januzaj goes down inside the area and again the ref books him for a dive!
At the Stretford End that is a bold call - but it looks like the right one. Wayne Rooney does not agree. Neither do 65,000 fans or so...
Post update
Man Utd 1-2 Arsenal
Phil Neville
BBC Radio 5 live
"Time is running out, but there's one thing these Arsenal players know is that United will get one more opportunity on goal before time is up."
Post update
Man Utd 1-2 Arsenal
Hit the big man stuff from the hosts now as they float a succession of balls at Marouane Fellaini. Per Mertesacker is earning his corn, flicking one out of the air nicely. Arsenal are six minutes away from the last four.
Post update
Man Utd 1-2 Arsenal
A few glum faces in the stands at Old Trafford as Arsenal look to see this one out.
Post update
Man Utd 1-2 Arsenal
Phil McNulty
BBC Sport chief football writer
"All getting very messy here at Old Trafford. Manchester United getting panicky with only 10 minutes left to save their hopes of a trophy this season. Referee Michael Oliver is coming under huge pressure - but Angel Di Maria was utterly senseless to tug at his shirt to see a second yellow."
Post update
Man Utd 1-2 Arsenal
Phil Neville
BBC Radio 5 live
"Louis van Gaal has broken with his coaching mentality and is standing on the edge of the technical area. It's something he rarely does, but it just shows the enormity of the situation."
Text us on 81111
Man Utd 1-2 Arsenal
Andy from Cannock: "This is ridiculous! At the end of the game, refs going to whip his top off and unveil his Arsenal shirt!!!"
Steve Huish from Surbiton: "Brilliant refereeing, spot on."
Opinion split. It was ever thus...
Post update
Man Utd 1-2 Arsenal
Wayne Rooney skims a free-kick into the Stretford End, Unitd playing 3-3-3 now which is a first...
Join the debate at #bbcfacup
Matt McGlone: That's what referees should do for me. It's not petty, they should be in charge and command the respect more often.
David Turner: Referee has been spot on in everything, Di Maria had to go there. Best refereeing performance I've seen in ages.
Post update
Man Utd 1-2 Arsenal
Referee Michael Oliver is being kept busy. Martin Keown wished him luck before the game and he may need it. He gives the hosts a free-kick right on the edge of the box...
Post update
Man Utd 1-2 Arsenal
Fans clapping off someone who has been sent-off - explain that to me again. One of my pet hates.
Angel Di Maria has let his side down here hasn't he? Arsenal fans are singing about Wembley, and they're now just over 10 minutes away. And a man up.
Post update
Man Utd 1-2 Arsenal
John Murray
BBC commentator
"Angel Di Maria walks off the field and they're applauding him. But for goodness sake, two yellow cards for that behaviour, he's cost his side a place in the semi-finals. He grabbed the referee's shirt and you simply cannot do that."
RED CARD
Man Utd 1-2 Arsenal - Angel Di Maria
Confusion! Angel Di Maria is now off, and it looked like he grabbed referee Michael Oliver's shirt after he had been booked. You can't do that.
YELLOW CARD
Man Utd 1-2 Arsenal
Angel Di Maria is booked for diving as he throws himself to the deck - that is very tame.
Post update
Man Utd 1-2 Arsenal
Phil Neville
BBC Radio 5 live
"I still can't get over that save from David De Gea, as the ball came in, it's great technique from Cazorla and De Gea scrambles across there to push it away so there's no chance on the rebound."
Join the debate at #bbcfacup
Andrew Morris: No width to United's play and crowd each other out. LvG has no clue. United are just poor and it's depressing to watch
Neal Collins: Interesting to see Welbeck flout the "gentleman's agreement" on celebrating goals scored against former club. No love lost!
GREAT SAVE!
Man Utd 1-2 Arsenal
What a save! David De Gea keeps Manchester United in the tie with a superb stop. Arsenal carve them open on the left, the cross is stood up, they are queuing up, Santi Cazorla gets plenty on the volley and De Gea reaches for it like Dhalsim! Brilliant.
SUBSTITUTION
Man Utd 1-2 Arsenal - Welbeck off
This is what you call an attacking sub - Adnan Januzaj on for Marcos Rojo. I've no idea what the formation will be now.
Arsenal replace Danny Welbeck, who is roundly booed, with Olivier Giroud.
Post update
Man Utd 1-2 Arsenal
Phil Neville
BBC Radio 5 live
"How many times have we seen when the ball goes out to the left for Arsenal, Alexis Sanchez drops his shoulder and cuts inside and causes all manner of problems for Man United."
Post update
Man Utd 1-2 Arsenal
Genius from Alexis Sanchez, picking a cross out of the sky with a touch of Nou Camp class and beating Antonio Valencia in one movement, drawing the foul.
Sanchez thumps the free-kick at David De Gea.
Post update
Man Utd 1-2 Arsenal
That last scheduled train from Manchester to London Euston is just leaving. If you're reading this and you need it - you've missed it.
Post update
Man Utd 1-2 Arsenal
Last 20 minutes then. Who's going to do a Ryan Giggs for Manchester united? Or are Arsenal going back to Wembley? She wore a yellow ribbon etc...
Text us on 81111
Man Utd 1-2 Arsenal
Ade: "A player celebrating against a former club?! What is going on?! Isn't that against the rules nowadays?"
Join the debate at #bbcfacup
Daniel Hemmings: You've got to feel for De Gea, he needs some defenders in front of him!
Nick Staddon: Good to see Welbeck celebrating against his former team, they didn't believe in him, Arsenal did!
Damian Fogarty: And that's why Welbeck is on instead of Giroud. Big pitch favours speed.
Post update
Man Utd 1-2 Arsenal
You can say what you like about Marouane Fellaini, but chip a ball to the back post and he's a menace. The Belgian climbs well to thump in a header and Wojciech Szczesny has to watch it all the way to gather it in.
The two sets of fans trade derogatory chants about strikers Danny Welbeck and Robin van Perise, who have swapped clubs. Who got the better deal?
Post update
Man Utd 1-2 Arsenal
Phil McNulty
BBC Sport chief football writer
"The rising noise levels around Old Trafford carry a hint of desperation as well as a desire to urge Manchester United forward. So much riding on these next 25 minutes for United and manager Louis van Gaal."
Text us on 81111
Man Utd 1-2 Arsenal
Dan in London: "You can have lucky wins, put Rooney in different positions and have a clipboard but persist with this horrible defence and Man Utd are going nowhere fast."
SUBSTITUTION
Man Utd 1-2 Arsenal
Hector Bellerin is hauled off before he gets sent-off. Calum Chambers is the man sent on to take his place at right-back.
CLOSE!
Man Utd 1-2 Arsenal
More trauma for Chris Smalling! He puts one over the bar from four yards out after a corner whips through the six-yard box. What a chance!
Post update
Man Utd 1-2 Arsenal
Phil Neville
BBC Radio 5 live
"The Arsenal bench are hurriedly organising to make a change to get Bellerin off."
YELLOW CARD
Man Utd 1-2 Arsenal
Marcos Rojo is booked for a wild challenge and Hector Bellerin is perhaps lucky not to see a second booking, followed by a red! He and Ashley Young tangle, they both go down and they are both already on a yellow...
Text us on 81111
James Marshall: Wayne Rooney's worth his weight in gold for United.
Matt in Leicester: Would love to see £37m Juan Mata come on for Fellaini, I reckon his link up with Di Maria, Young and Rooney would be far more effective. But LVG doesn't seem to value him, strange!
Join the debate at #bbcfacup
Sophie Manders: Danny Welbeck! What a guy.
Post update
Man Utd 1-2 Arsenal
Phil Neville
BBC Radio 5 live
"Brilliant centre forward play from Danny Welbeck, he smelt the danger, he sensed there was going to be an error. The speed just to get to that ball and then get round De Gea, I just wonder if his sale will come back to haunt Man United?"
Post update
Man Utd 1-2 Arsenal
Danny Murphy
BBC One
"What a gift for Arsenal. Danny Welbeck hasn't had one of his best games. But he keeps working, he keeps going, he keeps chasing."
GOAL
Man Utd 1-2 Arsenal - Danny Welbeck
I take it all back Danny Welbeck! He's not had a good game but he's put Arsenal ahead after a horror show at the back from Manchester United. Antonio Valencia's backpass is woefully undercooked, Welbeck is in on David De Gea, he gets there first and toes it around the keeper before sliding in the loose ball. He celebrates too against his old club. Wildly.
YELLOW CARD
Man Utd 1-1 Arsenal
Another booking, and it's for Ashley Young as he suplexes Danny Welbeck out on the touchline. United getting ragged perhaps but hang on, here's Angel Di Maria, looking like an ex-Real Madrid player for once, beating a man and shooting just wide from 22 yards.
Post update
Man Utd 1-1 Arsenal
Phil McNulty
BBC Sport chief football writer
"Scrappy start to the second half but Arsenal are playing on Manchester United defender Chris Smalling's nerves in and out of possession - and he is giving them plenty of encouragement."
Text us on 81111
Man Utd 1-1 Arsenal
Ben from the Wirral: "Chris Smalling must have had a traumatic experience with a football when he was younger. He looks absolutely terrified whenever it comes near him."
Post update
Man Utd 1-1 Arsenal
Phil Neville
BBC Radio 5 live
"I think Daley Blind is really struggling with that central midfield role. The game just seems to be passing him by there at the moment, he can't seem to handle the pace."
YELLOW CARD
Man Utd 1-1 Arsenal
Marouane Fellaini earns himself a booking for two clumsy hacks in a matter of seconds. The 5-a-side special that one, a slow, languid hack to trip his man up.
Join the debate at #bbcfacup
Andrew Thatcher: #Arsenal fans must question why many players like Walcott, the Ox, Ramsey, and Wilshere spend more time injured rather than playing
Paul Collins: Marcos Rojo is the best defender in the world... at passing back to his own goalie. Wow.
Post update
Man Utd 1-1 Arsenal
Arsenal on top since the break I reckon. Every time it comes to Danny Welbeck the move breaks down though. He's struggled on his Old Trafford return.
Post update
Man Utd 1-1 Arsenal
The crowd getting edgy now. The 100mph tempo of the first half has slowed to more like 70, but the mistakes keep coming in midfield. Olivier Giroud is warming up for Arsenal, can he get on and replace Danny Welbeck maybe?
Post update
Man Utd 1-1 Arsenal
Phil Neville
BBC Radio 5 live
"Good save from De Gea in the end. Composed goalkeeping as it just took a deflection from Alexis Sanchez's shot."
Post update
Man Utd 1-1 Arsenal
Oooh, dreadful touch from Chris Smalling opens the back door and Santi Cazorla dives through it. He runs in on goal and finds Alexis Sanchez on his left. Sanchez shoots but it takes a big floaty deflection and is easy for David De Gea.
Join the debate at #bbcfacup
Shane Daly: This game will have a later winner, hopefully it will be a United goal.
Martin McNamara: Pundits are saying this is an entertaining game? Well if you like pub football where no-one can string 5 passes together!
Lawrence Brooks: Phil Jones coming on to take the set pieces #philosophy
Text us on 81111
Man Utd 1-1 Arsenal
John in Doncaster: "For the first time in ages, Arsenal have a better bench than Man Utd."
Post update
Man Utd 1-1 Arsenal
Danny Murphy
BBC One
"I have some sympathy for Oxlade-Chamberlain. He never seems to stay in the team long enough because of injuries. He showed in the first half what he is capable of."
Post update
Man Utd 1-1 Arsenal
Wayne Rooney has been finding himself all over the field in recent weeks when operating as a midfielder, but he's done all of his work in the Arsenal half this evening. It's paid dividends so far...
SUBSTITUTION
Man Utd 1-1 Arsenal
Aaron Ramsey is on for the stricken Alex Oxlade-Chamberlain. Theo Walcott is also warming up.
Post update
Man Utd 1-1 Arsenal
Alex Oxlade-Chamberlain stretches and twang goes the hamstring, Marcos Rojo finds Wayne Rooney and heads wide on the stretch. Oxlade-Chamberlain is done here I reckon. You can't run off a torn hamstring.
Post update
Man Utd 1-1 Arsenal
Phil Neville
BBC Radio 5 live
"With Phil Jones going in to centre defence it gives more speed in that central area. United struggled a couple of times in the first half when Arsenal played ball in to that central area."
Post update
Man Utd 1-1 Arsenal
Michael Carrick's first rangefinder is bang on the money, an arcing 45-yard pass out to Ashley Young on the wing. Hector Bellerin in a mess under it, as comfortable as Monty Panesar taking a steepling catch at long on.
Bellerin misses it altogether and he's lucky that Young doesn't take advantage.
Post update
Man Utd 1-1 Arsenal
Phil Neville
BBC Radio 5 live
"I think the change in midfield is tactical. Herrera was struggling up against Cazorla a couple of times in that first half. I think it must be an injury to Luke Shaw, there was nothing to suggest he was struggling through poor form."
Post update
Man Utd 1-1 Arsenal
Angel Di Maria earns a nice round of applause after beating two men on the wing. This is the best he's played for a while. The crowd start the second half a bit quiet, that first 45 was pretty taxing on the old vocal cords though.
KICK-OFF
Man Utd 1-1 Arsenal
Marcos Rojo will move to left-back, Phil Jones at centre-back. Here we go!
SUBSTITUTION
Man Utd 1-1 Arsenal
Luke Shaw will have plenty of time to look at his boots Pete, as he's been hooked at the break as part of a double change. He's replaced by Phil Jones, with Michael Carrick on for Ander Herrera.
Post update
Man Utd 1-1 Arsenal
Former Manchester United keeper Peter Schmeichel to BBC Sport: "Both teams look nervous, the individual mistakes are incredible. Luke Shaw needs to look at his boots. He has been sliding all over the place and giving Arsenal space."
Post update
Man Utd 1-1 Arsenal
Roy Keane
Match of the Day, BBC Sport
"I think United have looked quite composed. I think Louis van Gaal will be fairly happy with this. Get the ball forward a bit quicker, especially to Wayne Rooney and they will be in the right areas."
Post update
Man Utd 1-1 Arsenal
Here we go, the teams are back out of the tunnel. More of the same please, more of the same.
Post update
Man Utd 1-1 Arsenal
Martin Keown
BBC Sport
"I just feel Arsenal are running with it too much, they need to pass it more. With Welbeck, they've got a match-winner in this game. Get the ball to him and he can punish United down the middle."
Text us on 81111
Man Utd 1-1 Arsenal
Steven in Manchester: I honestly can't remember the last time Fellaini won a free kick. He gets pushed and pulled all over but because of his size it seems referee's aren't willing to give anything. Noticed it's a problem Peter Crouch has as well.
Adebayo Akinfenwa can't buy a free-kick in the lower leagues Steve. The big men find it hard
Post update
Man Utd 1-1 Arsenal
Martin Keown is getting plenty of stick for his defending during that goal from Ryan Giggs in 1999...
Join the debate at #bbcfacup
Richard Fawcett: Probably the best attacking first half performance I've seen by #ManUtd under #LVG but still look shaky defensively
Ravi Shah: Would be nice if they had a draw. Both teams play a replay would be good.
Peter Neal: Di Maria looks a different player from recent weeks with United playing with pace. Rooney has to play up front every week.
Post update
Man Utd 1-1 Arsenal
Ian Wright on Match of the Day
BBC Sport
"I don't think Arsene Wenger will be happy. For me as a forward player, when they are playing nice, it's nice. But the main focal point [Mesut Ozil] isn't doing enough and I don't think Arsenal are keeping the ball well enough."
Post update
Man Utd 1-1 Arsenal
Who's going to argue with Roy Keane? Not me.
Let's hope for more of the same after the break though. We don't want another draw or a replay.
Post update
Man Utd 1-1 Arsenal
Roy Keane
Match of the Day, BBC Sport
"I think we'll see more of the same in the second half. The mentality of the attacking players on the pitch, that will just suit United. I think United have just got a touch more quality going forward."
Post update
Man Utd 1-1 Arsenal
Phil Neville thinks Michael Carrick is coming on at the break. Calm it down a touch?
See the goals
Don't forget you can see the goals in the highlights tab at the top of the page.
Post update
Man Utd 1-1 Arsenal
Roy Keane
Match of the Day, BBC Sport
"When Wayne Rooney's up on his own through the middle, he's as good as anyone else in the game there. He's got the quality and the ability to finish in those positions. I think the manager's been trying to prove a point over the last month or so playing him out of position."
Post update
Man Utd 1-1 Arsenal
Ian Wright on Match of the Day
BBC Sport
"I'd like to see Danny Welbeck hold the ball up a little bit more. Maybe he's a bit nervous."
Post update
Man Utd 1-1 Arsenal
Alan Shearer
BBC One
"It is an absolute no brainer to have Wayne Rooney up front, and not in midfield."
Post update
Man Utd 1-1 Arsenal
Roy Keane
Match of the Day, BBC Sport
"I was looking at that Arsenal goal from the defending point of view and the lack of character and commitment shown is just woeful. The lads have just downed tools there. It's an absolute schoolboy error and United have given Arsenal so much time and freedom there. That was shocking and absolutely disgraceful."
Text us on 81111
Man Utd 1-1 Arsenal
Mich in Leeds: Danny Welbeck's performance has been the perfect example of why Man Utd sold him.
Post update
Man Utd 1-1 Arsenal
Danny Murphy
BBC One
"I'm surprised Wojciech Szczesny is back in. He looks a bag of nerves. His kicking hasn't been great and there was one incident when he put his team in a world of trouble."
Post update
Man Utd 1-1 Arsenal
Excellent and liberal use of 'disgraceful' from Roy Keane as he analyses Manchester United's defending for Arsenal's goal.
Post update
Man Utd 1-1 Arsenal
Phil Neville
BBC Radio 5 live
"I thought it was a real entertaining first half. Arsenal have just shaded it for me with the movement in midfield."
Post update
Man Utd 1-1 Arsenal
Roy Keane
Match of the Day, BBC Sport
"It's been a decent game, nice and open. Plenty to enjoy for the supporters, but the managers won't be too happy as it's too open at times. Good thing United got the equaliser so quickly as it was a shocking goal to concede."
Post update
Man Utd 1-1 Arsenal
Manchester United had six attempts on goal, Arsenal five. End-to-end stuff at times.
Post update
Man Utd 1-1 Arsenal
Danny Murphy
BBC One
"The first half has been great, really entertaining. Both sides have had good spells."
Post update
Man Utd 1-1 Arsenal
Phil McNulty
BBC Sport chief football writer
"Excellent first 45 minutes from two teams playing as if their hopes of a trophy rest entirely on the FA Cup. Arsenal are playing with ambition, with Alexis Sanchez a class act, while Angel Di Maria is making inroads down the flanks, as emphasised by his cross for Wayne Rooney's header. Enthralling second half in prospect."
HALF-TIME
Man Utd 1-1 Arsenal
Wonderful game Well done one and all.
Watch Arsenal's goal again
If you've missed any of the key moments in this match, you can watch them again via the highlights tab throughout the evening. The Arsenal goal is in there now, with Rooney's to follow any minute.
Post update
Man Utd 1-1 Arsenal
Phil Neville
BBC Radio 5 live
"It's a really tense atmosphere inside the stadium. Both sides are really committed here and want to go through in this tie."
Post update
Man Utd 1-1 Arsenal
I was at Wembley last May when Santi Cazorla delivered a peach of a free-kick into the top corner of the Hull net, he looks up to take another free-kick form a similar range but this time he can't beat David De Gea in the United net.
Chances at either end as first Alexis Sanchez beats two men but can't shoot, and then Marouane Fellaini hits one at Wojciech Szczesny after a nervous clearance form the Pole.
GREAT SAVE!
Man Utd 1-1 Arsenal
Angel Di Maria in again down that right, he latches on to another 'long ball' from Antonio Valencia and this time does shoot. Not the most powerful drive but a good save from Wojciech Szczesny all the same.
Post update
Man Utd 1-1 Arsenal
Phil Neville
BBC Radio 5 live
"If Angel Di Maria had taken that fantastic ball from Wayne Rooney on his right foot, he'd have been in on goal there."
Post update
Man Utd 1-1 Arsenal
What a ball! Wayne Rooney puts it on to Angel Di Maria's foot with a gem of a clip over the top. Di Maria needs to smash it first time though and he doesn't want to. Chance has gone.
First half almost gone. It's sailed by.
Post update
Man Utd 1-1 Arsenal
Danny Murphy
BBC One
"The game has calmed down a bit which is to be expected after that frantic 10 minute spell. But I think we will get another goal."
Post update
Man Utd 1-1 Arsenal
Alexis Sanchez is a joy to watch, he really is. Signing of the season? He leaves two United men on their backsides with a jagging run. Even Mesut Ozil is putting tackles in, it's a committed performance from all 22 men thus far.
Join the debate at #bbcfacup
Mark Tomlinson: Look what happens when Rooney is actually played in his natural and best position! Great header and goal!
Post update
Man Utd 1-1 Arsenal
Phil Neville
BBC Radio 5 live
"Ashley Young is hugging that left touchline. As soon as he gets that ball out wide, he's driving on and looking to get past Hector Bellerin and be really positive."
Text us on 81111
On Monreal's goal
Alex in Cardiff: Chris Smalling caught ball watching when he should have realised Valencia had moved across and covered his position. Has never, and will never, be Manchester United quality.
Paul in Manchester: That goal shows why Chris Smalling is not good enough. Didn't have the intelligence to stay out in the full back position.
YELLOW CARD
Man Utd 1-1 Arsenal
Sloppy from Angel Di Maria to take too long in midfield, he's stripped of the ball and then pulls down Alexis Sanchez. Ander Herrera is booked in fact, it was a sandwich challenge.
Join the debate at #bbcfacup
Jason: Are we finally seeing the Di Maria we've waited for all season? His passing has been sublime today!
Post update
Man Utd 1-1 Arsenal
Wayne Rooney has scored in his last three FA Cup games against Arsenal - he's never won the trophy though. You may be surprised to hear that. I was.
Will he add it, will he lift it, this year?
Join the debate at #bbcfacup
Daniel Woodley: Two fantastic goals so far. End-to-end game and not one for defences
Post update
Man Utd 1-1 Arsenal
That's why you've been dropped son! Wojciech Szczesny, seemingly relegated to Arsenal's Cup keeper, makes a total hash of collecting a cross and is very lucky that he doesn't drop it at the feet of Wayne Rooney for a tap-in. There's no time to breathe in the game, gripping stuff.
CLOSE!
Man Utd 1-1 Arsenal
David De Gea with another save for his 2014-15 collection, getting down well to push out a header form Danny Welbeck. More good work from Alex Oxlade-Chamberlain down the right to pick him out.
Post update
Man Utd 1-1 Arsenal
Danny Murphy
BBC One
"When Wayne Rooney plays as a striker you know he is going to get goals. It's a great response from Manchester United. It's not the first ball Di Maria has put in from the right-hand side. It's whipped in with pace and what a header."
PENALTY APPEAL
Man Utd 1-1 Arsenal
Brilliant game this now. Arsenal have a good shout for a penalty as Mesut Ozil helps the ball on for Danny Welbeck, Marcos Rojo has a hand on his shoulder and the striker goes down. Nothing given...
Join the debate at #bbcfacup
Rob Meech: Not only does Nacho Monreal look like Peter Crouch but he can finish like him too!
GOAL
Man Utd 1-1 Arsenal - Wayne Rooney
We wanted a good game and we are getting one!
Manchester United level after a brilliant ball in from £60m man Angel Di Maria. It's a gem of a cross from the right, Wayne Rooney is between two defenders and meets it with a flying header Keith Houchen would be proud of.
Post update
Man Utd 0-1 Arsenal
Phil Neville
BBC Radio 5 live
"Nacho Monreal has got a large debt to play to Oxlade-Chamberlain, he beat three players on the edge of the box and then had the awareness to slip the ball to Monreal. Then he had the composure to finish it off, but it was all about Oxlade-Chamberlain for me that goal."
Post update
Man Utd 0-1 Arsenal
Danny Murphy
BBC One
"Game on. Arsenal have looked dangerous every time they have attacked. It's a cool finish from the left-back."
Post update
Man Utd 0-1 Arsenal
That is only Nacho Monreal's second goal for Arsenal. It wasn't quite Nigel Winterburn at Stamford Bridge, but a fine goal nonetheless. Can Manchester United respond to it?
GOAL
Man Utd 0-1 Arsenal - Nacho Monreal
Who had a punt on Nacho Monreal for first goalscorer?! Well done.
What a goal it is too. Mesut Ozil finds Alex Oxlade-Chamberlain on the right, the England man cuts inside and glides past Luke Shaw, Chris Smalling and Antonio Valencia before picking out left-back Monreal inside the area. He has one touch, and beats David De Gea at his near post.
A fantastic team goal.
Post update
Man Utd 0-0 Arsenal
Phil McNulty
BBC Sport chief football writer
"Marouane Fellaini marauding forward for Manchester United - and interesting to see that Arsenal have detailed Per Mertesacker to track his every move at set-pieces. United may not be unhappy about that as the giant German has been found wanting in that area on occasions this season."
But the key question is who is taller - Fellaini or Mertesacker? Take our quiz and find out.
Post update
Man Utd 0-0 Arsenal
Can we not knock it?! Both sides give the ball away with every touch in a torrid spell of play. Danny Welbeck's first touch is averaging about 15 yards at the minute. We've got the intensity we wanted, just lacking the composure and class...
Post update
Man Utd 0-0 Arsenal
Danny Murphy
BBC One
"I'm really pleased to see Oxlade-Chamberlain in the starting line-up. It's a great run, he's a powerful lad and so difficult to defend against."
Join the debate at #bbcfacup
Matt Collingwood: Easy to see why United struggle to create chances - the lack of movement is awful.
Jim: As a Spurs fan I honestly can't decide who I want to lose this.
Post update
Man Utd 0-0 Arsenal
Arsenal now get forwards well, Alex Oxlade-Chamberlain sprinting into the area but he is betwixt and between a shot and a cross, clipping a nondescript ball across goal.
Moments later Oxlade-Chamberlain again leaves two defenders for dead and goes down under Marcos Rojo's tackle.
Post update
Man Utd 0-0 Arsenal
Phil McNulty
BBC Sport chief football writer
"There is a real big game feel about the atmosphere inside Old Trafford tonight for this FA Cup quarter-final. Arsenal manager Arsene Wenger is perched on the edge of his technical area but do no expect to see any small talk with his Manchester United counterpart Louis van Gaal. He, as ever, is sitting well away from the action clutching his clipboard. He has barely been seen on the touchline all season, but his assistant Ryan Giggs is down there relaying his manager's orders."
Post update
Man Utd 0-0 Arsenal
Phil Neville
BBC Radio 5 live
"Ryan Giggs has just come out on to the touchline and he's had a word with Ander Herrera to say you've got to stay tighter to Santi Cazorla. A couple of times he hasn't tracked the run and Cazorla has gone on unmarked."
Post update
Man Utd 0-0 Arsenal
That's why Marouane Fellaini plays. Lovely control at the far post to gather in a fine crossfield pass from Angel Di Maria, he picks out Ashley Young running into the box but Young is always stretching for it and screws the shot wide.
Post update
Man Utd 0-0 Arsenal
Just a reminder that we haven't had a first-half goal in any of the FA Cup quarter-finals yet. Is tonight the night?
Hector Bellerin gallops onto a chipped through ball, his first touch is ace but he can't control a tricky shot from the angle. Pretty even stuff. Arsenal are happy to sit off Manchester United for long periods.
Post update
Man Utd 0-0 Arsenal
Phil Neville
BBC Radio 5 live
"It's in that midfield area that United have to get more of a grip with Ander Herrera and Daley Blind. Santi Cazorla is causing them a few problems at the moment. He's playing more central and it strikes me that he seems much happier playing that way. Lots of the play is going through him at the moment."
Post update
Man Utd 0-0 Arsenal
Arsenal do well to play out of trouble at the back, I feared for them when Per Mertesacker was faffing with it as the last man but the giant German and goalkeeper Wojciech Szczesny just about clear their lines.
Arsenal then break, Santi Cazorla slides a pass into the run of Danny Welbeck but it hits his heel and bounces away.
Post update
Man Utd 0-0 Arsenal
Danny Murphy
BBC One
"Fellaini has got to shoot - I can't believe has has come back in on his wrong foot. But positive build-up from Manchester United."
Join the debate at #bbcfacup
David Simpson: 87 minutes on a yellow card for Bellerin vs Young. Tasty.
Adam Sibley: Think Arsenal need to be a bit sharper and a bit more focused and we have a good chance here.
Post update
Man Utd 0-0 Arsenal
Shoot man! Marouane Fellaini is slid through by Chris Smalling and can surely get a shot away on his left foot, but he comes inside though and the chance has gone.
Post update
Man Utd 0-0 Arsenal
Danny Welbeck and Wayne Rooney - likely to be England's front two under Roy Hodgson later this month? - have had three touches each so far. The fewest on the pitch.
Alexis Sanchez has had 12.
Post update
Man Utd 0-0 Arsenal
Nervy start from Arsenal full-back Hector Bellerin! He's already been booked and a terrible touch on the halfway line almost lets in Luke Shaw on the counter. Bellerin can't touch him or he's off, and he needs reinforcements to scramble back quickly.
Post update
Man Utd 0-0 Arsenal
Phil Neville
BBC Radio 5 live
"When I was speaking to the supporters outside the ground, they were looking forward to a United-Arsenal contest of the past. But, I look out there and I don't see any tough tacklers like there used to be, I see a lot of technical players instead."
Post update
Man Utd 0-0 Arsenal
Danny Murphy
BBC One
"It's been a bit nervy from Arsenal's defence - one needless free-kick, one needless corner. I still find it strange that Wayne Rooney is still taking free-kicks - he's a goal scorer."
Post update
Man Utd 0-0 Arsenal
We need more away fans at Premier League games. The atmosphere is miles better tonight than most at Old Trafford.
That's not a very popular opinion, I would imagine, but I'm sticking with it.
Arsenal's out ball so far is to Alexis Sanchez on the left.
Post update
Man Utd 0-0 Arsenal
Manchester United win a corner, load it up! Danny Welbeck is dragged back to help out but it's Wayne Rooney who meets the ball on the volley. He tries to hook it across goal but it runs right across the face of the goalmouth.
Arsenal can't get out, they left nobody up and United keep the ball.
Post update
Man Utd 0-0 Arsenal
Francis Coquelin took a bash to the nose a few moments ago and he needs some treatment, he'll be OK though. Good cut and thrust to the opening stages, both sides looking to get the ball forwards.
Post update
Man Utd 0-0 Arsenal
Phil Neville
BBC Radio 5 live
"That's put Hector Bellerin under some real pressure now and you've got to stay on the ground in circumstances like that, especially in the first five minutes."
YELLOW CARD
Man Utd 0-0 Arsenal
A very early booking! Hector Bellerin is rash, very rash, on Ashley Young and chops him down. Sunday League stuff from the Arsenal youngster.
Post update
Man Utd 0-0 Arsenal
Phil Neville
BBC Radio 5 live
"That was a good opportunity there for Alexis Sanchez. He cut inside and tried to bend it in to the top corner and there was some indecision there from Chris Smalling."
Post update
Man Utd 0-0 Arsenal
Alexis Sanchez running at Antonio Valencia? Total mismatch.
The Arsenal forward glides past the United right-back and gets a shot away. It is blocked by a red shirt and it could go anywhere. It rolls fortuitously into the arms of David De Gea. Almost first blood Arsenal.
Post update
Man Utd 0-0 Arsenal
The excellent 1999 semi-final is referenced by a chant about Patrick Vieira from the Stretford End as Nacho Monreal runs out of turf in their first attack down the left. Good tempo so far.
Post update
Man Utd 0-0 Arsenal
Phil Neville
Former Manchester United defender on BBC Radio 5 live
"In the past Arsenal have always come to this stadium in great form and they've always been a massive let down. Let's see if they can prove me wrong this evening."
Post update
Man Utd 0-0 Arsenal
Angel Di Maria starts wide on the right and is found very early on. Early Manchester United possession.
KICK-OFF
Man Utd 0-0 Arsenal
Arsenal, in a deeper shade of blue, get us under way...
Join the debate at #bbcfacup
Man Utd v Arsenal (19:45 GMT)
Alistair Wiseman: Giroud benched = Wenger prioritising a cup he can't win (CL) & league he can't win, over a cup he can retain. I find this disgusting
LINE-UPS
Man Utd v Arsenal (19:45 GMT)
Man Utd: De Gea, Valencia, Smalling, Rojo, Shaw, Ander Herrera, Blind, Di Maria, Fellaini, Young, Rooney. Subs: Da Silva, Jones, Mata, Falcao, Januzaj, Carrick, Valdes.
Arsenal: Szczesny, Bellerin, Mertesacker, Koscielny, Monreal, Coquelin, Cazorla, Oxlade-Chamberlain, Ozil, Sanchez, Welbeck. Subs: Gibbs, Giroud, Walcott, Ramsey, Chambers, Martinez, Akpom.
Referee: Michael Oliver (Northumberland)
Post update
Man Utd v Arsenal (19:45 GMT)
We want plenty of intensity tonight Roy. The sides enter to the Rocky fanfare, it sounds like a wonderful atmosphere at Old Trafford. Showpiece occasion. Showpiece performances?
Post update
Man Utd v Arsenal (19:45 GMT)
Roy Keane
Match of the Day, BBC Sport
"It's great to look back at the clips, great memories of some great games. It was such a clash of characters in the contests. In those days, you knew if you got a result against Arsenal, you had a chance of winning a title.
"I think these days, these games are just lacking that bit of intensity."
Post update
Man Utd v Arsenal (19:45 GMT)
Here we go then - the teams are in the tunnel. Wayne Rooney's eyes are set dead ahead. Let's do this!
'I don't want to become like Arsenal'
Man Utd v Arsenal (19:45 GMT)
Manchester United fans Josh, Nathan and Dave speaking to us outside Old Trafford. Nathan (centre) says. "The FA Cup is more important than the top four to me. Why? I don't want us to become like Arsenal: reaching the Champions League but winning no trophies. This club is all about silverware.
"Wayne Rooney has a great goalscoring record against Arsenal and I think he'll score twice in a 2-1 win, so long as he plays up front. Playing him in midfield is pointless."
Post update
Man Utd v Arsenal (19:45 GMT)
Manchester United manager Louis van Gaal: "What's the plan? That we beat Arsenal! That's the most important thing in a Cup tie. Arsenal are one of the best teams in the Premier League but I have noticed that they have played more defensively lately. With a lot of success.
"It is not so easy to recover from an injury for Michael Carrick and then play in a Cup tie. Daley Blind is doing well and Ander Herrera too. Carrick has to wait.
"I have been to Wembley as a spectator but not as a coach and that is more interesting."
Post update
Man Utd v Arsenal (19:45 GMT)
BBC Red Button
Just to give you even more options tonight, TV viewers can watch with BBC radio 5 live commentary if they press their Red Button once the action is under way.
Post update
Man Utd v Arsenal (19:45 GMT)
What was so special about the games between Arsenal and Manchester United 10 years ago? That's the question Gary Lineker puts to the panel.
"I hated Roy Keane. Hated him," says Ian Wright. A nervous glance to his right. "I don't hate him now..."
Post update
Man Utd v Arsenal (19:45 GMT)
In his interview with Martin Keown last week Arsene Wenger said that he still regrets the defeat at Old Trafford which ended his Arsenal side's unbeaten run at 49 games. As 50 is a landmark which would have stood forever.
Forty-nine games unbeaten! Incredible to look back on that now.
Post update
Man Utd v Arsenal (19:45 GMT)
Ian Wright on Match of the Day
BBC Sport
"When you look at their win against Manchester City a while back, everyone thought a change had happened to Arsenal. Since then we haven't seen anything like that again. Arsenal haven't been fluent. This is the kind of big game where you want Arsenal to put down a marker."
Post update
Man Utd v Arsenal (19:45 GMT)
Match of the Day
Former Manchester United captain Roy Keane: "I've not been surprised by where United are currently under Louis van Gaal. There's been so many changes over the years at the club, it's expected. Lots of experienced players leaving and people shouldn't be surprised at where they're at.
"There's been progress over the last few months. People are obsessed with getting in to the top four, but you also need to win trophies.
"What's helping is they're getting decent results, performances haven't been great, and the fans would like some quicker play in the final third."
Post update
Man Utd v Arsenal (19:45 GMT)
Kick-off just 10 minutes away now. This has got to be a good game, it just has to be. Right?
Monday Night club
Man Utd v Arsenal (19:45 GMT)
BBC Radio 5 live
Tonight's match is also live on BBC Radio 5 live and Kelly Cates will have all the latest football debate and build-up from Old Trafford in the Monday Night Club from 19:00 GMT.
Guests include Phil Neville, Martin Keown and 5 live commentators John Murray and Alan Green.
When's the draw?
Man Utd v Arsenal (19:45 GMT)
The draw for the semi-finals will take place on BBC1 at around 21.45 GMT, with ex-United keeper Peter Schmeichel and presenter Dermot O'Leary picking the balls.
The numbers to look out for will be:
1 Liverpool or Blackburn Rovers
2 Bradford City or Reading
3 Manchester United or Arsenal
4 Aston Villa
The semi-final ties are to be played on 18 and 19 April.
Join the debate at #bbcfacup
Man Utd v Arsenal (19:45 GMT)
Shohidur Rahman: I'm really surprised Michael Carrick isn't starting. For me when he's fit, he's a guaranteed starter. Also would've started Falcao.
LIVE NOW!
Man Utd v Arsenal (19:45 GMT)
Match of the Day
Here we go then. Live on BBC One and at the top of this page.
Press play now!
'FA Cup over top four'
Man Utd v Arsenal (19:45 GMT)
Arsenal fans James and Mohsin, speaking to our reporter Alistair Magowan outside Old Trafford. James (left) says "I don't think we've beaten Manchester United at Old Trafford since 2006, but you've still got to come along and show the faith.
"I'm the same with Arsene Wenger. I don't think we've stagnated under him. He's bought in some talented players in Mesut Ozil and Alexis Sanchez, but he needs to sign more than one top-class player each season, like Chelsea and Manchester City."
Mohsin (right) says: "I'd take the FA Cup again this year over the top four. I'm fed up of fourth place being seen as a trophy and let's face it, we're not going to win the Champions League. Hopefully, though, a win here can give us hope for the European tie against Monaco."
Post update
Man Utd v Arsenal (19:45 GMT)
Marouane Fellaini is not the most popular man in Manchester is he? You'll change your tune should he scramble in a late winner...
Join the debate at #bbcfacup
Man Utd v Arsenal (19:45 GMT)
Andy Daly: Reasonably happy with that #MUFC lineup, but I wonder how Mata & Januzaj feel sitting on the bench when Fellaini is in 1st XI?
Marv Andre Khala: Rafael and Mata should be starting. I don't like this idea of starting with Fellaini as a striker.
Aniekan Inyang: Gunners to hurt Utd with pace.
Post update
Man Utd v Arsenal (19:45 GMT)
Phil McNulty
BBC Sport chief football writer at Old Trafford
"Arsenal have a dismal record against Manchester United in recent years. They have not won at Old Trafford since 2006 and United have won 11 and lost only one of the last 15 meetings in all competitions.
"United have not sparkled this season under Louis van Gaal, although they have been grinding out results - is the time right for the Gunners to finally change the storyline of this fixture?"
Post update
Man Utd v Arsenal (19:45 GMT)
'Get stuck in' says Roy Keane as Gary Lineker goes through his lines in the Match of the Day studio.
'That's what I want, tackles flying in' adds Ian Wright. Kick-off is 20 minutes away, and live BBC One coverage is now seven minutes away.
Keano in the house
Man Utd v Arsenal (19:45 GMT)
Big news from Old Trafford - Roy Keane is smiling! The ex-Man Utd captain is in position and he looks like he's having a great time alongside Alan Shearer as the pair have a bit of a chinwag. Just like old times.
Join the debate at #bbcfacup
Man Utd v Arsenal (19:45 GMT)
Luke A Howell: Utd 3 Arsenal 2, not the score line, number of Brits on display.
Colin Groom: Two unanswered questions. Will Ozil finally turn up in a big game for Arsenal? Has Wenger mastered a zip?
Tom Bradshaw: So nervous, not because United are good but because they're lucky and you can't train for that.
Post update
Man Utd v Arsenal (19:45 GMT)
Martin Keown wishes referee Michael Oliver 'good luck' as he warms up on the Old Trafford pitch. Could be a big game for Oliver tonight. Not as busy as it would be if Keown was playing mind...
Post update
Man Utd v Arsenal (19:45 GMT)
How are your nerves? It should be a cracking atmosphere tonight with 10,000 Arsenal fans packed in at Old Trafford.
The usual allocation for away fans at Old Trafford in the Premier League is nearer to 3,000. Raise the roof!
Join the debate at #bbcfacup
Nathan Hingley: Januzaj should be starting, Di Maria impact sub. Mata wasted on the bench.
Pete Haines: Arsenal will bottle it as usual. 3-1 @ManUtd
Dara Sheahan: LVG needs to let the players off the leash and trust their instincts. That'll let the stars shine bright.
Text us on 81111
Man Utd v Arsenal (19:45 GMT)
Rick in Manchester: Phil Neville says we should be impressed with Louis van Gaal's team set up, yet he possesses a team that has had £200m-plus investment over the last two years and they're awful to watch.
'Hugely important match'
Man Utd v Arsenal (19:45 GMT)
BBC Radio 5 live
Former Manchester United goalkeeper Peter Schmeichel speaking to Kelly Cates: "When you play Arsenal, it's one of the biggest ties possible. Two of the most successful clubs in the history of this competition.
"It's realistically the only opportunity either side has left this season to win a trophy, so it's a hugely important match."
'Greatest game'
Man Utd v Arsenal (19:45 GMT)
Former Manchester United defender Phil Neville
"In 20 years of playing football, that match at Villa Park in 1999 was the greatest game I was ever involved in.
"It was the game that went on to win the treble for us. Martin Keown has nothing but nightmares from that game.
"This fixture was probably one of the greatest I played in, it had everything in terms of a rivalry. Great players, great goals, controversy, the lot.
"Lots of things were always happening around the action and tonight will be no different."
Party like it's 1999
Man Utd v Arsenal (19:45 GMT)
April, 1999.
Mr Oizo was at number one with his annoying, bass-heavy 'Flat Beat', the minimum wage was introduced at £3.60 an hour for workers over 21, and these sides served up one of the great FA Cup games - perhaps one of the best games I've ever seen - in the semi-final replay at Villa Park.
Younger readers may not have ever seen the classic - so fill your boots here! It was a brilliant, brilliant match.
Stunning goals, a red card, a penalty miss, disallowed goals - you name it. Ryan Giggs' winner alone is a legendary moment. Though surely Lee Dixon or Martin Keown could have got a challenge in?
I would love it, love it, if tonight's game was half as good...
Post update
Man Utd v Arsenal (19:45 GMT)
Former Manchester United keeper Edwin van der Sar: Done with the working day and full speed home to watch the FA Cup.
Team news
Man Utd v Arsenal (19:45 GMT)
Luke Shaw starts his third FA Cup game for Manchester United, the 19-year-old in for suspended defender Jonny Evans. Otherwise it is the same line-up as the one that won 1-0 at Newcastle last Wednesday.
Arsenal manager Arsene Wenger makes five changes to the team that won 2-1 at QPR last time out, with former Manchester United striker Danny Welbeck returning to the team. Keeper Wojciech Szczesny is back after illness, while defenders Laurent Koscielny and Nacho Monreal return along with midfielder Alex Oxlade-Chamberlain.
Striker Olivier Giroud, who has scored seven and assisted four goals in his 11 FA Cup appearances for Arsenal, has to make do with a place on the bench.
Manchester United XI: De Gea, Valencia, Smalling, Rojo, Shaw, Blind, Herrera, Di Maria, Fellaini, Young, Rooney.
Arsenal XI: Szczesny, Bellerin, Mertesacker, Koscielny, Monreal, Coquelin, Cazorla, Oxlade-Chamberlain, Ozil, Sanchez, Welbeck.
Post update
Man Utd v Arsenal (19:45 GMT)
'Panic' by the Smiths rings out at Old Trafford as Wojciech Szczesny goes through his warm-up. Will the recalled Arsenal keeper bring calm, or panic, to his back four tonight?
'Arsenal seem to bottle it at Old Trafford'
Man Utd v Arsenal (19:45 GMT)
Former Manchester United defender Phil Neville
"There's still the fierce rivalry between the two sides. Tonight will be a different game from what we saw back in 1999. It will be more technical, there's no Roy Keane, Patrick Vieira, David Beckham or Ryan Giggs. What I see is more technical players.
"Arsenal have always come to Old Trafford full of confidence, but never performed.
"They always seem to bottle it. But they've got to perform tonight and look to hit United on the counter. It's an intriguing game and whoever wins tonight, it will give them that momentum to finish in the top four."
5 live Sport
Man Utd v Arsenal (19:45 GMT)
BBC Radio 5 live
There's full match commentary on BBC Radio 5 live from 19:45 GMT.
Join John Murray and Alan Green with former Manchester United defender Phil Neville in the summariser's chair on 909 and 693 MW.
You can also listen by choosing the Live Coverage options at the top of this page as well as through the BBC Sport app on mobile and tablet.
Post update
Man Utd v Arsenal (19:45 GMT)
Phil McNulty
BBC Sport chief football writer at Old Trafford
"11 v 11 at Old Trafford tonight. A meeting between the FA Cup joint record winners Man Utd and Arsenal.
"If Louis van Gaal is to win a trophy in his first season in charge at United, then it has to be with a 12th triumph in this great tournament. And with Arsenal realistically out of the title race and fighting for survival in the Champions League after a 3-1 loss at home to Monaco in the last 16, the stakes are arguably higher than they usually are when these two fierce rivals meet."
Text us on 81111
Man Utd v Arsenal (19:45 GMT)
Which former Manchester United or Arsenal players would you most like to bring back into the current side, and why?
Logan Bond: Cristiano Ronaldo back at Manchester United. Will never forget the roar that went through my house when he scored that free-kick at the Emirates in the Champions League semi-final.
Rich in Somerset: Bergkamp, Bergkamp, Bergkamp.
Sin in Birmingham: Can we have a new spine please at Man Utd? Stam, Keane & Cantona would do the job!
Post update
Man Utd v Arsenal (19:45 GMT)
Former Manchester United defender Gary Neville: Looks like Rooney up top/Fellaini behind.
Team News
Man Utd v Arsenal (19:45 GMT)
Arsenal
Arsenal make five changes from the side which beat QPR as former United man Danny Welbeck starts up front.
What sort of reception will he get?
Join the debate at #bbcfacup
Antony Reader: I think we'll see something from Falcao tonight.
Saim Naveed: Whatever Van Gaal says he wants the FA Cup as much as a top-four finish.
'Still on target'
Man Utd v Arsenal (19:45 GMT)
Former Manchester United defender Phil Neville
"Manchester United have been getting lots of criticism for the performances.
"It's not free-flowing, but you can't argue with only two defeats in 22 games. Louis van Gaal's objective at the start of the season was to finish in the top four and win a trophy and he's still on target for that.
"So I think you have to be impressed with the way he has set up his team."
Team News
Man Utd v Arsenal (19:45 GMT)
Man Utd
Manchester United make one change from the side which beat Newcastle - Luke Shaw replaces the suspended Jonny Evans.
Full team news to follow.
Post update
Man Utd v Arsenal (19:45 GMT)
Arsene Wenger looks incredibly relaxed, he's been chatting with Martin Keown down by the tunnel, signing autographs and now having an extensive chat with somebody else. Not a care in the world. What team has he chosen tonight? We shall find out in a few minutes.
Watch it with Roy
Man Utd v Arsenal (19:45 GMT)
BBC One
Tonight's match is live on BBC One and you can see every kick, tackle and hopefully goal live from Old Trafford from 19:30 GMT.
Gary Lineker will be joined by a heavyweight panel of pundits including Roy Keane, Alan Shearer and Ian Wright.
Yes that's right - Roy Keane sitting next to Alan Shearer. This could be interesting.
Commentary comes from Guy Mowbray and Danny Murphy.
Post update
Man Utd v Arsenal (19:45 GMT)
Phil McNulty
BBC Sport chief football writer at Old Trafford
"All quiet at Old Trafford - for now. Man Utd v Arsenal. FA Cup quarter-final."
Should Di Maria do more?
Man Utd v Arsenal (19:45 GMT)
BBC Sport pundit Robbie Savage
"The reason there was such a buzz when United bought Angel Di Maria from Real Madrid in August is that he was up there with the best players in the world.
"He was man of the match in last season's Champions League final, which Real won, and he had a great World Cup. The very best players in the world are able to grab games by the scruff of the neck and lift their team when they are not playing well.
"Alexis Sanchez has been a great example of that with the way he has regularly made things happen for Arsenal on the days when they have been average and have needed his help to help set the tempo in attack.
"There is no way you could say that Di Maria has done the same for United while they have been short of their best form.
"Yes he still works hard but, if anything, his performances have been getting worse, not better."
Read more from Robbie here.
Join the debate at #bbcfacup
Goonerama: Re: former player to bring back - it's got to be Vieira. Titan. Giant. Colossus. Just what we need in CM right now
Abdulahi: Patrick Vieira, self-explanatory.
'Not convinced by Van Gaal'
Man Utd v Arsenal (19:45 GMT)
Manchester United fans Sheldon and Marsha have been talking to our reporter Alistair Magowan outside Old Trafford.
Sheldon (left) says: "This is a big game for both clubs and their managers because it can provide a springboard for the rest of the season.
"I'm not totally convinced by some of Louis Van Gaal's decisions so far but as much as I'd like us to taste glory in the FA Cup and go to Wembley, I understand what the manager is saying by wanting to reach the Champions League next season. Both are important."
Top-four more important?
Man Utd v Arsenal (19:45 GMT)
Manchester United boss Louis van Gaal says a top four Premier League place is more important than winning the FA Cup.
United are currently in fourth in the top flight - a point behind Arsenal - and haven't won the FA Cup since 2004.
Van Gaal said: "To finish in the first four is a fantastic result and for us at Manchester United even more I think.
"If you win the FA Cup you are not in the Champions League but you have won a title."
What do you reckon? Are both possible?
Post update
Man Utd v Arsenal (19:45 GMT)
The current Arsenal team are at Old Trafford, former United man Danny Welbeck leading the way. He should know where he's going...
Join the debate at #bbcfootball
Old but gold
All this talk of Mikael Silvestre's team selections has got us looking back at the past.
Which former Manchester United or Arsenal player would you most like to bring back into the current side, and why?
Would Bryan Robson sort out the Old Trafford midfield? Could Marc Overmars add the spark that's missing at the Emirates? George Best? John Jensen?
Let us know at #bbcfacup, pop on to the BBC Sport Facebook page or BBC Sport's Google+ area.
You can also text us on 81111 in the UK only - don't forget to say who you are and where you are texting from.
Progression? Or regression?
Man Utd v Arsenal (19:45 GMT)
It's a similar story for Arsenal. Ten years ago they had just gone unbeaten for a whole season, so perhaps the only way was down from there.
Thierry Henry is not included - he was injured for the 2005 final. If he was available he's a shoo-in, which could see Alexis Sanchez miss out. He's one of only two current players in the team, with Laurent Koscielny getting the nod at the back ahead of Philippe Senderos.
Are both teams worse than a decade ago?
Progression? Or regression?
Man Utd v Arsenal (19:45 GMT)
First of all, Mikael Silvestre has picked himself in the combined United side. And let's face it, we'd all do the same if we could.
The only players from the current side to get a look in are goalkeeper David De Gea, captain Wayne Rooney and British transfer record signing Angel Di Maria.
Roy Keane, Cristiano Ronaldo and Paul Scholes have proved irreplaceable...
Progression? Or regression?
Man Utd v Arsenal (19:45 GMT)
These sides met in the final in 2005, a dour game settled on penalties, with Arsenal eventually winning with Patrick Vieira's last touch for the club.
Much has changed in the ensuing decade, a new stadium, a new manager, hundreds of millions of pounds' worth of players - but have the sides improved?
We asked Mikael Silvestre - who played for both clubs - to pick combined sides made up of today's squads, and those who played in the 2005 final.
Join the debate at #bbcfacup
Man Utd v Arsenal (19:45 GMT)
Gary Lineker
BBC Sport
Big games need big panels. For MUFC v AFC, Alan Shearer, Roy Keane & @IanWright0 Three men who could give it, take it and deliver. @BBCOne 7.30
Post update
Man Utd v Arsenal (19:45 GMT)
The Manchester United team bus has just arrived at Old Trafford. Will we see some changes to the side tonight? Michael Carrick and Phil Jones have walked in with their team-mates. We won't know the team for around half an hour.
All aboard
Man Utd v Arsenal (19:45 GMT)
Working out the time of the last train home can often give supporters headaches when travelling to midweek fixtures - including for Arsenal fans this evening.
With the last scheduled train from Manchester Piccadilly to London Euston this evening being 21:15 GMT (some 20 minutes into the second half), Arsenal have chartered two special trains to get fans back to London tonight.
Prices were also considerably cheaper than if you were just travelling for work or pleasure - £30 for a first class return and £20 for a standard return.
Can't imagine the carriage scenes looked much like when these Fulham fans caught a special service to Ipswich in 1957.
Sacrifice the Cup?
Man Utd v Arsenal (19:45 GMT)
Arsenal boss Arsene Wenger has admitted sacrificing his side's FA Cup chances in previous seasons to boost their prospects of European glory.
Arsenal's Champions League hopes this year may be all but over after a disastrous 3-1 defeat at home to Monaco last month, but historically the FA Cup has had to play second fiddle for Wenger.
"The FA Cup was badly positioned before the Champions League - you always had decisions to make," said Wenger.
"A player who was a bit on the edge - what do you sacrifice? It was always the FA Cup in the end.
"Sometimes as well I did not sacrifice the FA Cup years before and we paid the price because we lost one or two important players two or three days before an important game."
Post update
Man Utd v Arsenal (19:45 GMT)
In the draw rehearsal which has just taken place, Manchester United or Arsenal were drawn against Bradford or Reading, by the way.
The picture will become clearer in a few hours' time.
Who's in the draw?
The draw for the semi-finals of the FA Cup will take place after tonight's game with Aston Villa the only side assured of a place in the last four after their 2-0 win over West Bromwich Albion.
Liverpool's 0-0 draw with Blackburn means they both join Bradford and Reading, who also drew 0-0, in the hat.
The draw will take place on BBC1 at around 21.45 GMT, with ex-United keeper Peter Schmeichel and presenter Dermot O'Leary picking the balls.
The numbers to look out for will be:
1 Liverpool or Blackburn Rovers
2 Bradford City or Reading
3 Manchester United or Arsenal
4 Aston Villa
The semi-final ties are to be played on 18 and 19 April.
Reading and Bradford will replay their last-eight tie at the Madejski Stadium on Monday, 16 March with the date for the Blackburn-Liverpool game still to be confirmed.
Post update
Man Utd v Arsenal (19:45 GMT)
I hope I do speak for everyone when I call for a Cup classic tonight.
Give me goals, excitement, mistakes, drama, a red card or two - just action and antics by the bucketload.
Save the best to last?
Man Utd v Arsenal (19:45 GMT)
Dear Messrs Van Gaal and Wenger,
It has been a testing weekend for us all. Three FA Cup quarter-finals have come and gone with a paltry two goals shared between them.
We had as many pitch invasions as goals - with all of the meaningful action coming at Villa Park. Of the eight quarter-finalists, only West Brom have been eliminated.
The creaking calendar is struggling to accommodate any more replays, BBC One have had to move EastEnders in the middle of a big storyline, and 10,000 Arsenal fans have come to Manchester for tonight's match.
We really, really want a great game. We need goals, incidents, late drama, intrigue, suspense - we need the magic back. Do you remember 1999 by any chance? Something like that would be just great.
If you could please oblige, we'd be ever so grateful.
Yours sincerely,
The footballing public...