The hosts come into this match off the back of three consecutive Premier League wins without conceding a goal, lifting them into the top four of the table but still 12 points adrift of leaders Manchester City.
United, meanwhile, are eight points behind the pace-setters, but could close that gap to five with a victory against their old rivals today as City are not in action until Sunday.
Make sure you don't miss a moment of the action courtesy of our minute-by-minute updates below.
ARSENAL: Cech; Koscielny, Mustafi, Monreal; Bellerin, Ramsey, Xhaka, Kolasinac; Ozil, Lacazette, Sanchez
ARSENAL SUBS: Ospina, Mertesacker, Coquelin, Wilshere, Iwobi, Welbeck, Giroud
MANCHESTER UNITED: De Gea; Lindelof, Smalling, Rojo; Valencia, Matic, Pogba, Young; Lingard, Lukaku, Martial
MANCHESTER UNITED SUBS: Romero, Darmian, Blind, McTominay, Herrera, Mata, Rashford
An incredible match comes to an end at the Emirates Stadium as Manchester United hold on for a crucial 3-1 victory over Arsenal, who missed a plethora of chances to get something out of the game.
United were two up inside 11 minutes after a couple of defensive errors from Arsenal, setting the tone for a breathless and frantic contest. Arsenal found David de Gea in inspired form but finally pulled a goal back through Alexandre Lacazette early in the second half, only for Jesse Lingard to restore the two-goal cushion shortly after the hour mark.
Arsenal's hope was renewed when Paul Pogba was shown a straight red card, but there was no way back for the hosts. Thanks for joining our live coverage of the match!
90+6 minFULL TIME: Arsenal 1-3 Manchester United
90+3 min MAN UTD SUB: A third and final change for the visitors sees Marcus Rashford replace Young.
90+1 min There will be FIVE minutes of added time at the end of this one! We want more!
89 min YELLOW CARDS! Herrera and Sanchez both go into the book for an altercation in the aftermath of that Monreal header.
88 min SAVE! Monreal forces a save from De Gea with a looping header, but the real talking point came seconds earlier when Arsenal were denied a clear penalty after Darmian had brought Welbeck to ground inside the area.
87 min YELLOW CARD! Mourinho wants a red card for Koscielny here as he trips Lukaku when the Belgian was threatening to race through on goal, but the referee only gives yellow.
85 min We're seeing replays of that De Gea double-save, and it really is world-class from the keeper. It is a huge moment in the game too as that would have made it 2-2, when just seven minutes later Lingard made it 3-1.
83 min SAVE! De Gea is needed again here as Iwobi's strike deflects up and threatens to dip in, but De Gea just helps it over the crossbar.
81 min The chances have dried up a little over the past 10 minutes of this match, but the action continues to arrive and no-one can accuse these two sides of failing to entertain them this evening.
79 min Just over 10 minutes remaining for Arsenal to get themselves back into this match! They do deserve something from this game, but time is beginning to run out now.
77 min ARSENAL SUB: Wenger is looking to take full advantage of that red card as Olivier Giroud replaces Kolasinac.
76 min MAN UTD SUB: Mourinho responds with a change as Matteo Darmian replaces Lingard.
74 min I think this match has now had a bit of everything! Paul Pogba sees a straight red card for United with a little over 15 minutes remaining, ruling him out of the Manchester derby amongst other games.
It is the right decision too as he goes into a studs-up challenge on Bellerin, catching the wing-back right on the knee joint. That was a nasty one.
74 min RED CARD! Paul Pogba (Manchester United)
72 min YELLOW CARD! No complaints from Bellerin here as he goes into the book for a crunching challenge on Young.
70 min ARSENAL SUB: Arsene Wenger is going for this one - on comes Danny Welbeck for Xhaka.
69 min Arsenal have just over 20 minutes remaining to salvage something from this match, but in all honesty they should be at least level already. They have had so many chances today.
67 min MAN UTD SUB: Mourinho wants to see this game out now - on comes Ander Herrera in place of Martial.
65 min SAVE! De Gea makes yet another save, this time from Sanchez's drilled effort from range. Arsenal have their 10th corner of the match.
63 min Mourinho will be a lot happier now! United restore their two-goal advantage, and once again it is really poor defending from Arsenal.
It comes from another United counter as Pogba drives forward down the right flank, shrugging off a challenge from Koscielny far too easily and dancing around him on the byline. There is poor marking in the middle too as Lingard escapes his marker, and Pogba plays the ball across goal to leave Lingard with the simplest of finishes.
63 min GOAL! Arsenal 1-3 Manchester United (Jesse Lingard)
62 min United are trying to slow the tempo down here, and you can understand why. Arsenal are swarming all over them and, while it is a thriller for the neutrals, Mourinho won't be happy with what he is seeing right now.
60 min The only stoppages in the action we are getting here are through injuries, and Matic needs treatment after taking a heavy blow to his head in the area.
58 min YELLOW CARD! All of this action, and this is the first card of the game as Rojo goes into the book.
56 min DOUBLE SAVE! Unbelievable! This game continues to get better and better, and we have just seen one of the best double-saves you will ever see too! De Gea, take a bow, because this is magnificent.
Lacazette breaks into the box and drills a low strike towards goal which De Gea does incredibly to get down to, and he then reacts to make a huge follow-up save with his feet to deny Sanchez! Ridiculous.
55 min SAVE! This is a more routine stop for De Gea as he collects Iwobi's tame header.\
54 min Thankfully, I look like being proved wrong about the second half not being able to live up to the first. Even with more than half an hour remaining I can say with confidence that this will go down as one of the best games of the season.
52 min SAVE! At the other end Arsenal test De Gea again with a powerful strike from the edge of the box which draws another good save from the keeper!
51 min OFF THE POST! This is incredible! United break up at the other end and Lingard finds himself clean through on goal, but Cech makes a brilliant stop to send the ball looping up and against the post. The ball then drops to Martial, but Monreal makes the block from point-blank range!
49 min Now then! Manchester United opened the scoring within four minutes of the first half, and Arsenal have done the same at the start of the second!
It is a strange goal in many ways as United's defence all go to sleep thinking that Ramsey is offside. The midfielder has timed his run to perfection, though, and has the wherewithal to knock the ball back to Lacazette when inside the box too. Lacazette has all the time in the world to lash it home with the United defence still statues, and suddenly Arsenal are back in it!
49 min GOAL! Arsenal 1-2 Manchester United (Aaron Ramsey)
48 min I highly doubt whether we will see a similarly entertaining half, simply because it may not be possible. Arsenal need to push for goals still, though.
46 min KICKOFF: Manchester United get us back underway for this second half. More of the same please!
45+3 min HALF TIME: Arsenal 0-2 Manchester United
45+1 min SAVE! This is bonkers. Absolutely bonkers. Arsenal cannot believe they haven't scored here, and it would have been a Lukaku own goal. The striker is falling backwards and inadvertently turns the ball towards his own goal, and it takes a sensational reflex save from De Gea to claw the ball away. Yet another scramble ensues, but once again United survive.
45+1 min There will be three minutes of added time at the end of this thrilling first half.
44 min SAVES! De Gea is called into two flying saves in quick succession from both Arsenal full-back. Bellerin's is the better effort, striking a fine long-range effort towards the far corner which De Gea is at full stretch to save. Seconds later Kolasinac fires a dipping effort on goal which De Gea again parries away.
43 min Yet another break from United almost catches Arsenal out as Pogba gives the ball to Martial, who beats Xhaka far too easily before putting a ball into the box which Monreal does well to clear.
42 min CHANCE! Big chance for Arsenal, but Matic produces a stunning block to deny Ramsey. The ball breaks to the midfielder inside the box and he looks destined to nestle it home, but Matic reads it and throws himself in the way of the ball.
41 min Arsenal break into the box again as Lacazette and Sanchez exchange passes really well, but United just about hang on once again.
39 min We have just six minutes until half time now - this opening 45 has flown by so far! Arsenal are still in this one and look capable of scoring, but they also look capable of conceding too. This one is so finely poised.
37 min SHOT! Pogba gives the ball away in a dangerous position and Ozil gives the ball to Iwobi, but the winger blasts a poor effort well off target.
36 min CHANCE! Arsenal threaten a goal back as Lacazette pulls the ball back for Ozil, who meets it with a crisp half-volley which De Gea does well to hold on to.
34 min CHANCE! There is no time to stop for breath here! United launch yet another break and have the numerical advantage this time, with Pogba leading the charge down the right flank. His cross into the box is looking for an unmarked Lukaku, but Kolasinac gets the ball first and Cech needs to fall on it to deny an own goal.
32 min CHANCES! How have Arsenal not scored here?! It is a proper goalmouth scramble which United somehow survive without getting a goal back!
Sanchez's ball into the box deflects to Lacazette, who misses his initial kick but then gets the ball back, reaches the byline and dribbles back into the middle. De Gea is diving all over the place but Lacazette bides his time before eventually seeing his shot deflect up onto the crossbar. It then falls to Iwobi, whose blocked shot falls to Xhaka, but his low effort clips the outside of the post!
30 min OFF THE LINE! Ozil floats his free kick over the wall, but Young reads it, darts back and clears it just in front of his line. De Gea looked like he might have been struggling to reach that one.
29 min Another chance for Arsenal to test De Gea from a free kick as Rojo brings Sanchez to ground just outside the area. This one is perhaps a little too close if anything, though...
28 min Arsenal do need to be wary about committing too many men forward, even if they are two goals down. Every time United break they seem to have so much space, and it is easy to see them putting Arsenal to the sword if that continues.
26 min We so often see Mourinho try to shut up shop away to big teams, but this game has been really open and entertaining so far. I'm sure Mourinho would want his side to be a little less open now they are two goals ahead, but from a neutral point of view it has been a great game so far.
24 min Mourinho has been unhappy with how this match has developed since that second goal, and he takes an injury break while Jesse Lingard receives treatment to have a long talk with Pogba about it.
22 min Lacazette gets a touch to a Ramsey strike and loops the ball towards goal only to see it land on the roof of the net, although the linesman's flag was raised.
21 min SAVE! Ramsey tries his luck from outside the area, but his strike is tame and easy for the keeper to collect.
20 min CHANCE! Golden chance for Arsenal to halve the deficit! Koscielny loops a header into the box from a corner and Lacazette gets the wrong side of Rojo, stretching out and getting a toe to the ball from point-blank range. De Gea blocks it with his legs and the ball trickles agonisingly past the post, but he didn't know anything about it.
19 min Mayhem inside the Manchester United box as two defenders, De Gea and two Arsenal players are all chasing a bouncing ball which eventually goes behind for a corner. This time it was the hosts who hit United on the break.
18 min United have a good chance to break from an Arsenal corner as Pogba feeds a pass through to Lukaku, who all too easily is in acres of space on the right. The striker powers past Ramsey before putting his cross into the box, but he picks out an Arsenal defender rather than Lingard.
17 min Arsenal have responded quite well to that second goal and have been on the front foot since, but it is a long way back for them now. The Gunners need the next goal without a doubt.
15 min ARSENAL SUB: Here is the change as Alex Iwobi replaces the injured Mustafi.
13 min Things go from bad to worse for Arsenal - Mustafi appears to have picked up an injury during that incident and may not be able to continue. Alex Iwobi is the man warming up, interestingly.
11 min Incredible! Manchester United are two goals to the good inside the opening 11 minutes, and it is another poor piece of defending from Arsenal which gifts them it!
Koscielny gives the ball across to Mustafi, who has time despite Lingard chasing him down. The defender takes too long over it, though, and Lingard nips in to steal possession. From there is is clinical from United as Lukaku finds Martial, who brilliantly flicks the ball around the corner for Lingard to finish when one on one with the keeper.
11 min GOAL! Arsenal 0-2 Manchester United (Jesse Lingard)
11 min More cause for the United fans to be optimistic following that early goal...
9 min Sanchez goes for goal himself, but he fires the free kick straight into the solid Manchester United wall.
8 min Arsenal will have the chance to test De Gea for the first time here as Sanchez wins a free kick from Smalling in a very good shooting position...
6 min United could not have wished for a better start to this match. I questioned whether they would be cautious tonight or go for the win - well now they can afford to sit back and look to frustrate Arsenal. That is a big, big goal to get so early.
4 min What a start for Manchester United! They break the deadlock inside four minutes as Antonio Valencia scores his second Premier League goal of the season!
It is a dreadful pass square across defence from Koscielny and Valencia quickly pounces on it, beating Kolasinac to the ball. The wing-back then exchanges passes with Pogba on the edge of the box before collecting the return and drilling it through the legs of Cech!
4 min GOAL! Arsenal 0-1 Manchester United (Antonio Valencia)
3 min United win an early corner after they get forward well down the left flank, but Young's delivery comes to nothing. The visitors have settled into this quickly.
1 min KICKOFF: Here we go, then! After a false start, Arsenal get us underway at the Emirates!