Chances! Aaron Ramsey can't quite connect with a dinked ball over the top and Alex Oxlade-Chamberlain forces David de Gea into a fine, fine stop. Again!

Axel Tuanzebe does well to bustle Alexis Sanchez off the ball - he went down too easily. So Arsenal switch flanks to wide right.

Sanchez is found in the middle, again he tucks it in behind to Aaron Ramsey, whose cut-back finds Danny Welbeck. 

But it's Chris Smalling with the last-ditch block this time to protect David de Gea's net. 

The Gunners building...

Wayne Rooney has been in thick of the action for Manchester United, with only Michael Carrick and Henrikh Mkhitaryan having more touches than his 23.

But most of them are out on the left flank or, as Mark Schwarzer points out below, deep in the away midfield.

Image source, Opta

Suddenly action! 

Danny Welbeck pokes towards goal from an Arsenal corner - pinball in the box before Phil Jones throws his body in the way to clear. 

From the next corner Matteo Darmian outjumps Alexis Sanchez.

Image source, Reuters

Alright it really has slowed now. I take back what I said about this having an edge.

Alexis Sanchez, Arsenal's streetfighter with a sore lip, plays a one-two with Danny Welbeck on the edge of the box but the touch is heavy and Manchester United clear.

Down the pitch Juan Mata can pick out Henrikh Mkhitaryan - in acres of space - with a decent ball but his cross is poor.

Mark Schwarzer
Ex-Middlesbrough keeper on BBC Radio 5 live

Wayne Rooney drops deeper into midfield to get the ball because he's not in the game very much in that 'false 10' position.

But people get frustrated because he comes too deep and takes all the space in midfield where Carrick and Herrera want to get the ball.

With Wayne Rooney dropping alongside Michael Carrick in midfield, Manchester United don't really have anything to aim at playing long from deep. Instead it's out wide to Axel Tuanzebe, whose dart down the right is clipped short by Alexis Sanchez. 

Free-kick out wide in a decent position, turned into a corner as Arsenal clear, and Petr Cech comes with a big punch to claim.

Even steven(ish). Manchester United have shaded the possession in the opening 20 minutes, but most of it has been in their own third or midfield.

Manuel Neuer. Will that do?

Bit of a lull now as we go handball in centre midfield, offside, poor Arsenal corner. That good start has ebbed away.

Phil Johnson: Someone is going to have to convince me that De Gea isn't the best keeper in the world. United would be mid-table without him. 

But Manchester United now turn the ball loose and for a moment Danny Welbeck is away in the clear - found by Aaron Ramsey's pass. 

Quickly the blue United shirts swarm back to cover. Danger edged out of sight for the time being, and more time for Arsenal to build from deep. Jose Mourinho will be happy to let them have it there.

Space for Mesut Ozil as Manchester United shuffle behind the ball in reply to Arsenal possession. 

He can't find the killer opening he's always looking for - despite the unfashionable gait. The away side are defending deep and in numbers. Nothing given away.

Image source, Reuters

It was a quality stop. It might not be for the title, but there's a real edge to this match. 

Arsenal must win to have any hope of a top-four place. 

Manchester United have made an excellent start, despite all the Europa League as priority chat. They would be behind though, without David de Gea.

Mark Schwarzer
Ex-Middlesbrough keeper on Radio 5 live

That's a wonderful save by David de Gea. He got down really quickly. It's a good strike on goal by Aaron Ramsey, denied by the brilliance of De Gea.

It's poor though from Wayne Rooney and Arsenal sweep forward on the counter. 

Aaron Ramsey ghosts in behind, found by Alexis Sanchez's devious pass, and David de Gea earns his coin with a fantastic low stop to tip his vicious shot wide.

More space down the Arsenal left, Anthony Martial drifts inside but can't keep his balance, Ander Herrera picks up the baton and wins a corner. 

Manchester United's second of the match already.

Marcus: More chances in Arsenal United game in first five minutes than in whole Liverpool Southampton game.

A very decent chance for Anthony Martial is tipped wide of the Arsenal front stick by Petr Cech as a sweeping Manchester United move creates space down the right.

Brilliantly found by Wayne Rooney, Martial toe-poked it towards goal under pressure, couldn't quite direct it.

Axel Tuanzebe's high-top hairstyle is looking sharp. The 19-year-old right-back is making his Premier League debut today.

He's caught a little high up the pitch as Kieran Gibbs darts down the Arsenal left wing, but the cross comes to nothing as Alexis Sanchez is crowded out.

Image source, Getty Images

Mark Schwarzer
Ex-Middlesbrough keeper on Radio 5 live

The Europa League is probably a more realistic route to the Champions League for Manchester United - by resting players that indicates where his priorities lie.

But for Arsenal they desperately need to finish in the Champions League places.