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...

Rob Meech: Not only does Nacho Monreal look like Peter Crouch but he can finish like him too!

Image source, Getty Images

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.

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."

Danny Murphy
BBC One

"Game on. Arsenal have looked dangerous every time they have attacked. It's a cool finish from the left-back."

Image source, Getty Images

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?

Image source, PA

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.

Phil McNulty
BBC Sport chief football writer

Image source, AP

"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.

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...

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."

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.

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.

Phil McNulty
BBC Sport chief football writer

Image source, Reuters

"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."

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."

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.

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.

Phil Neville
BBC Radio 5 live

Image source, AP

"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."

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.

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."

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.