Cech was a virtual spectator for his team's brilliance but he made a telling contribution a minute before half-time, saving with his left leg after Anthony Martial took advantage of Per Mertesacker's slip.

Van Gaal understandably opted for a double change at the interval, with Antonio Valencia and Marouane Fellaini replacing Darmian and Memphis Depay, who both endured halves to forget.

There was greater poise about the visitors after the resumption but Ozil fizzed an effort narrowly wide after his 52nd-minute free-kick came back off the wall.

Wayne Rooney, who displayed clear frustration when he was booked for a petulant foul on Ozil, was the next United player to extend Cech with a bouncing drive.

The ex-Chelsea man then came out with authority to thwart Bastian Schweinsteiger before Juan Mata looped a left-footed attempt over.

Substitute Alex Oxlade-Chamberlain clipped the crossbar with a neat lob in stoppage time, attempting to pile further misery onto Van Gaal's team as their run of three consecutive Premier League wins came to an end in truly chastening fashion.

•  

   

  That's all from me, Matthew Judge, and it has been a fantastic pleasure talking you through all of today's action from the Emirates. We hope you can join us again very soon. Take care!
•  

   

  Arsenal move above United into second place on goal difference after today's result in North London, with both sides locked level on 16 points behind leaders Manchester City. Next up for the Gunners is a trip to Watford while Van Gaal's men face Everton at Goodison Park, with each tie coming after the international break.
•  

   

  Wenger's men completely outclassed United in the first half and some of their football was scintillating. They defended well without possession, with Cech making a couple of big saves, in a complete performance from the Gunners.
•  

   

  The Gunners pick up their first Premier League win over United since 2011 as a brace from Alexis Sanchez and a solitary strike from Mesut Ozil sees off the Red Devils at the Emirates.
•  

   

  FULL-TIME: ARSENAL 3-0 MANCHESTER UNITED
• 90' + 1'

   

  The fourth official indicates that a minimum of two minutes will be added on to the second half. Arsenal are in possession at the moment and are closing in on three very big points on home turf.
• 90'

   

  Ramsey gets his head to a cross at the back post above a few United players but he fails to divert the ball towards goal as the ball trickles over the line for a free-kick to the visitors.
• 88'

   

  Martial runs to the left of Gabriel inside the penalty area and tumbles to the floor under pressure from Arsenal man, who runs away with the ball. There was no real protests from the visitors for a penalty there.
• 86'

   

  CLOSE! Oxlade-Chamberlain gallops down the right wing and sends in a low cross towards Giroud, who guides a right-footed shot straight down the throat of De Gea in a tame effort.
• 84'

   

  Carrick, who has done well with his passing from the middle of the pitch in the second half, feeds in Wilson but the United striker breaks the attack down as his first-time ball backwards to Rooney gets overcooked, sending the United skipper to the flank.
• 82'

   

  SubstitutionJuan Mata James Anthony Wilson
  Van Gaal rolls the dice for the last time today as Mata comes off in United's final alteration to proceedings. Wilson, lacking in match time this season, enters the pitch as his successor.
• 82'

   

  Wilson moves into a good pocket of space to try and receive a pass from Young but the flag raises for offside, though Mertesacker cuts the ball out anyway with solid reading of the game.
• 81'

   

  SubstitutionAlexis Sánchez Kieran Gibbs
  Sanchez, perhaps carrying a little tweak after being on the receiving end of several tough challenges today, comes off late on in the second half. Gibbs heads on in his place to try and see the game out for Arsenal.
• 80'

   

  It looks as though both sides are about to make their final changes now as Keiran Gibbs and James Wilson are both stripped in their respective kits on the touchline.
• 78'

   

  There's no real desire for a fourth from Arsenal as the Gunners have set out to protect their three-goal swing in this second half. They've done a good job at it as time continues to run out for United to turn things on its head.
• 76'

   

  Giroud, lacking the speed to move away from Smalling, holds the ball up well towards the dugout and tries to then play in a team-mate, but Schweinsteiger cuts out the pass for an Arsenal throw-in.
• 75'

   

  SubstitutionMesut Özil Alex Oxlade-Chamberlain
  Wenger makes his second substitution of the match as Ozil comes off to a warm reception here at the Emirates. The German, who is being replaced by Oxlade-Chamberlain, was simply amazing today.
• 75'

   

  SubstitutionTheo Walcott Olivier Giroud
  The fourth official's board goes up and Walcott trudges off the pitch with around 15 minutes of normal time left to play. Giroud runs on as his replacement and his aerial presence will give the Gunners a different outlet to hit.
• 74'

   

  Carrick feeds through a decent pass towards Martial who holds off Gabriel and drives a ball across the face of Arsenal's goal towards Rooney, but Mertesacker clears at the back post brilliantly.
• 72'

   

  Fellaini loses the ball to Coquelin and an Arsenal attack begins through Sanchez. The Chile international chooses not to play in Walcott and instead backtracks, buying a challenge off the United midfielder who lost the ball in the first place.
• 70'

   

  Gabriel takes a big risk at the back as he allows Martial to close him down inside his own half. The Frenchman creates a half chance for United as a result but Blind's stabbed pass towards Fellaini goes beyond him with Mertesacker putting the pressure on.
• 68'

   

  GOOD SAVE! Carrick's pass gets deflected off Rooney and into the path of Schweinsteiger. The German's touch lets him down and gives Cech the opportunity to rush off his line, be brave and punch away the danger.
• 66'

   

  Mata gets forward down the left and curls in a cross towards the middle of the penalty area but Cech comes off his line and calms things down with a comfortable save.
• 64'

   

  Carrick scoops the ball forward towards Martial but Mertesacker aims a leg forward to the ball and diverts it away from the young Frenchman. He's had little to do today the German but he has been solid whenever he has been called into action.
• 62'

   

  Fellaini steals the ball away from Walcott in the centre of the pitch and plays in Schweinsteiger, who shifts the ball from right to left down the flank but Coquelin clears his cross and sets up an Arsenal counter-attack.
• 60'

   

  Valencia gets at Monreal in a one-on-one battle for the first time in the second half and wins his side a corner off the Spaniard. The ball curls in towards the Arsenal box but it comes to nothing.
• 58'

   

  Van Gaal cuts a confused figure on the bench as he weighs up how to get his United side back into this game. On the basis of what we're seeing so far in the second half, it's hard to see how his players can do so with Wenger's charges looking so comfortable and oozing confidence.
• 56'

   

  Walcott wins a free-kick as Blind, struggling to keep up with the Arsenal man's pace, brings him down in his own half. The Gunners have started the better out of the two teams since the half-time break.
• 55'

   

  Yellow CardWayne Rooney
  Rooney picks up a yellow card for bringing down Ozil. The United man loses sight of the ball due to his opponent's quick feet and picks up a card for the same thing Coquelin done to him a few minutes before.
• 54'

   

  Ozil powers forward yet again down the left-hand flank and spins Rooney before the United skipper brings him down for a foul. Cazorla stands over the ball but he plays it short as Arsenal don't need to pump men forward anymore.
• 52'

   

  WIDE! Ozil drives a free-kick straight into Schweinsteiger in the wall but the ball bounces back into his path, and it takes a slight nick off a United defender to head out of bounds for an Arsenal corner. The replay shows that the rebound effort was going in without the deflection.
• 51'

   

  Yellow CardFrancis Coquelin
  Coquelin becomes the first Arsenal player to get booked by the referee today. He clearly fouls Rooney down the left wing when sticking close to him on a United counter-attack.
• 50'

   

  Valencia gets pressed superbly by Ozil and that forces the Ecuadorian to play the ball straight to Sanchez, who tries to curl a pass towards an onrushing Ramsey but the attack breaks down as Smalling steps in when Walcott got a touch to the ball.
• 48'

   

  Young drifts infield from the left past Ramsey and hits a shot towards Cech between the Arsenal sticks, but the former Chelsea shot-stopper gobbles the ball up comfortably.
• 46'

   

  SubstitutionMatteo Darmian Antonio Valencia
  Darmian heads off the pitch as United make it a double change in response to a collectively woeful first-half showing. Valencia runs onto the field as his replacement at right-back.
• 46'

   

  SubstitutionMemphis Depay Marouane Fellaini
  Van Gaal makes his first change of the game as he takes off Depay for Fellaini. United completely lost the midfield battle to Arsenal in the first half and the Belgian will add more physicality to proceedings, which should improve that.
• 46'

   

  Welcome back! Manchester United get us back underway for the second half here at the Emirates, with the Red Devils bringing on Valencia and Fellaini both coming on for the next 45 minutes.
•  

   

  The current crop of Arsenal players have often been criticised for their naiveness when it comes to defending but you can tell Wenger has demanded a response in that respect after losing to Olympiacos in midweek. So far they've worked hard as a unit off the ball and ensured United have created next to nothing, in a much more improved display.
•  

   

  Arsenal's front three of Ozil, Walcott and Sanchez have been excellent in the final third, causing so much mayhem in the United backline from the first whistle. The Gunners surged forward numerous times before taking the lead and Van Gaal's charges didn't know what him them.
•  

   

  Both groups of players head towards the tunnel for the half-time interval with United all set up for an ear-bashing from Van Gaal in the dressing room. Although Arsenal deserve huge credit for their oustanding, glorious football, the Red Devils were so off the pace in the first half it was unbelievable at times.
•  

   

  HALF-TIME: ARSENAL 3-0 MANCHESTER UNITED
• 45'

   

  WHAT A SAVE! Martial makes Mertesacker hit the deck when controlling Darmian's pass and he swivels and fires from point-blank range, but Cech diverts the ball away from his goal with an outstretched left boot. Sensational reactions from the Arsenal goalkeeper.
• 43'

   

  Depay picks up the ball from Mata and curls in a low cross from the left flank towards the back post, but Gabriel heads away too easily with just two United players inside the penalty area.
• 41'

   

  It's calm possession from Arsenal as they work it forward, then back and then forward again with hardly any United players getting anywhere near them in the process. It's wonderful from the Gunners but the work rate from their opponents for today was lacking badly there.
• 39'

   

  Walcott slides in on Schweinsteiger from Mata's paceless pass across the middle of the pitch and sets up another Arsenal breakaway, but this time it comes to nothing. It will be interesting to see how Van Gaal changes things at half time as United can't keep on losing the midfield battle so easily.
• 37'

   

  Martial brings the ball down on his chest from a long ball forward and looks to play in any United team-mates around him, but the Frenchman gets caught coming from an offside position and the attack breaks down.
• 35'

   

  Arsenal win the ball ahead of United again as it gets played into the path of Walcott, who marauds past Smalling and Blind but the official on that side of the pitch raises his flag for offside.
• 33'

   

  SO CLOSE TO MAKING IT 4-0! Sanchez picks up the baton after some good work from Ozil and Walcott and clips in a peach of a pass over the top of Young to Ramsey, who places his shot just past the post from close range.
• 31'

   

  Smalling wins a crucial header to prevent Walcott running in on goal, before Sanchez thinks he's in business for the counter-attack again but the referee blows his whistle as he penalises Monreal for a foul.
• 30'

   

  Yellow CardMatteo Darmian
  Sanchez drives forward down the left and Darmian, always losing out in the foot race, whips up the Arsenal man and therefore collects a caution as a result, meaning United now have both full-backs booked now.
• 29'

   

  Depay gets an initial half a yard on Bellerin down the flank but the Arsenal right-back, renowned for his blistering pace, catches up with him and blocks the United man's attempted cross for a throw-in.
• 27'

   

  United have had the lion's share of the ball since Arsenal's second but Wenger's men are falling back into a solid, compact shape and they're brilliantly denying the visitors any space to move into. Martial has barely had a touch or a sniff beyond the two Gunners centre-backs.
• 25'

   

  Cazorla picks up the ball deep inside United's half and weighs up a long shot as he drives a right-footed effort just wide of De Gea between the United sticks. Excellent again from Arsenal.
• 23'

   

  United are back on the ball and are keeping it well without really penetrating Arsenal. You have to feel, with the likes of Walcott and Sanchez on the breakaway, this is playing right into the hands of the Gunners. The gameplan has been executed to perfection so far.
• 22'

   

  Yellow CardAshley Young
  Young gets his name taken by the referee as he produces a tactical foul on Ramsey. The Welshman surges forward on the counter-attack for Arsenal and the Manchester United makeshift left-back dives in to prevent him from making it four.
• 21'

   

  Quick, accurate, incisive passing from Arsenal has destroyed United in this first half. Questions were asked about the Gunners beforehand, about whether they had the boldness to beat a top team this season, but they've responded to them magnificently so far.
• 19'

   

  AssistTheo Walcott
• 19'

   

   

   

  GoalAlexis Sánchez
  GOOOOOOOOOOOOOAAAALL!! It's 3-0 and it's two for Alexis Sanchez! Walcott picks up the ball deep inside United's half from Ramsey's cute pass and plays in the former Barcelona man, who lashes an effort into the top corner after getting a second bite of the cherry from Darmian's tackle.
• 17'

   

  Schweinsteiger collects the ball in the middle of the park and swings in a cross towards Martial at the back stick, but Mertesacker stretches his neck muscles as he stoops low to snuff out the danger. Solid defending from the World Cup winner.
• 15'

   

  Blind takes his time on the ball as United ponder ways to get themselves back into the game but Walcott rushes him and forces him to quickly play a pass sideways to Smalling. The Arsenal man was close to stealing possession and running towards De Gea one-on-one then.
• 13'

   

  Ramsey tries to latch onto the end of a pass with few players forward for Arsenal but Young crucially intercepts and plays it back to De Gea. The Gunners are finding so much joy down the left at the moment with Blind and Schweinsteiger in particular both struggling with the pace.
• 11'

   

  CLOSE! Sanchez picks up the ball just outside the United penalty area and tries to curl a low pass towards Walcott, again running in behind Blind, but it gets cleared in the nick of time. Arsenal's front three are different class so far.
• 9'

   

  United look absolutely stunned as Arsenal have been all over them right from the get-go in North London. Ozil has been right at the heart of their beautiful play while Blind is being horribly exposed for the Red Devils at the moment.
• 7'

   

   

   

  GoalMesut Özil
  GOOOOOOOOOAAAALLLL!! This is superb from Arsenal! Walcott latches onto a pass from Ozil and beats Blind for pace down the left-hand side, before he returns the favour and sets up his German team-mate to guide the ball beyond De Gea. Wonderful stuff again from the Gunners to double their lead!
• 7'

   

  AssistTheo Walcott
• 6'

   

   

   

  GoalAlexis Sánchez
  GOOOOOOOOOAAAAALLLL!! It's 1-0 to Arsenal! Ramsey threads through a delighful pass down the side of Blind to Ozil and the German picks out an onrushing Sanchez, who dinks the ball with the outside of his boot past De Gea at the near post. A sublime finish from the Chile international.
• 6'

   

  AssistMesut Özil
• 3'

   

  Cazorla pulls the strings early doors as he firstly plays in a corner which Carrick clears at the near post, before the Spaniard picks up the ball again and sets Sanchez up for a header which flies wide of De Gea's goal.
• 1'

   

  Arsenal get us underway here at the Emirates. The man in charge of the cards for today's encounter is Anthony Taylor.
•  

   

  Here we go! Both sets of players are stripped and raring to go as they leave the tunnel and enter onto the field in front of the glorious sunshine at the Emirates this afternoon. We are just moments away from seeing the action start.
•  

   

  A win for Arsenal today would put them on level points with United and therefore represents a great incentive for them. On the other hand, the Gunners have only won one Premier League game at home this season and the Red Devils are unbeaten in their last four visits to the Emirates.
•  

   

  MANCHESTER UNITED substitutes: Romero, Jones, Wilson, Valencia, Fellaini, Schneiderlin, McNair.
•  

   

  MANCHESTER UNITED (4-2-3-1): De Gea; Darmian, Smalling, Blind, Young; Carrick, Schweinsteiger; Mata, Rooney (c), Depay; Martial.
•  

   

  ARSENAL substitutes: Ospina, Debuchy, Gibbs, Giroud, Oxlade-Chamberlain, Chambers, Campbell.
•  

   

  ARSENAL (4-3-3): Cech; Bellerin, Mertesacker (c), Gabriel, Monreal; Ramsey, Coquelin, Cazorla; Sanchez, Walcott, Ozil.
•  

   

  TEAM NEWS: Van Gaal makes just two alterations to the team which started United's 2-1 victory over Wolfsburg in midweek. Both Ashley Young and Michael Carrick get the chance to impress from the get-go in favour of Antonio Valencia and Morgan Schneiderlin respectively, who each drop to the bench for this afternoon.
•  

   

  TEAM NEWS: Wenger has made four changes to the side which started Arsenal's 3-2 loss to Olympiacos in midweek, with Petr Cech returning between the sticks in favour of David Ospina. The Colombian shot-stopper drops to the bench as Per Mertesacker, Nacho Monreal and Aaron Ramsey also come into the first eleven for today's match.
•  

   

  The Red Devils are starting to look more and more like a Louis van Gaal side by the coming weeks and with United heading into today's affair with four straight wins in all competitions, things are looking rosy for them ahead of this afternoon's game.
•  

   

  It's been a difficult few days for Arsene Wenger and his Arsenal side after another dismal showing in the UEFA Champions League in midweek and it will be interesting to see how they can respond in the face of adversity today. Standing in their way this afternoon are Manchester United, who can return to the Premier League summit with a win in North London.
•  

   

  Good afternoon and welcome to our LIVE text commentary of today's mouth-watering Premier League clash between Arsenal and Manchester United from the Emirates Stadium. I'm Matthew Judge and I will be your host for the match, which kicks off at 4:00pm.