Former Arsenal and England centre-back Martin Keown
5 live Sport

"This is all about Arsene Wenger now, who has to earn his money. He will calm his team down and tell them they need to go for Monaco's throat. Arsenal haven't yet turned up in the final third, and Monaco have defended stoutly."

Bira King: That goal shows up the of wasteful play of Arsenal.

Harry Fisher: When will people realise Welbeck is nothing but a passenger in games like these? United lost patience, surely Arsenal will too.

Nathan: Looks like some more Last 16 misery for Arsenal...

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Image source, Getty Images

The half-time whistle goes and Arsenal pay the price for a lack of urgency in that half. Another bad first 45 minutes for an English side in the Champions League, after Manchester City found themselves 2-0 down to Barcelona at the same point last night.

...Santi Cazorla takes it, but it is too close to the Monaco keeper.

Danny Welbeck scampers away down the right and his pace proves too much for Elderson, who opts to stop him in his tracks with a lunging foul. Yellow card for the Monaco man and a free-kick for Arsenal...

Image source, Opta

Arsenal have had more possession - and slightly more of the territory. But they trail where it matters most.

Francis Coquelin goes in too heavy on goalscorer Geoffrey Kondogbia and picks up the first booking of the night. A frustrating goal for the hosts to concede, having looked relatively comfortable for much of the half.

Javel Bleach: Monaco lead at Arsenal! Who expected that?

Mike Simpson: Classic Arsenal. Even more patience required now.

Kerry Peter Parvin: Not a surprise with the way Arsenal have been playing. Yet again at the big stage the players don't turn up.

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So far it is an unhappy reunion for Arsene Wenger with his former side Monaco. He leans forward on his seat in the dugout, arms folded and deep in thought as Arsenal try to mount a response.

Former Arsenal and England centre-back Martin Keown
5 live Sport

Image source, Reuters

"Kondogbia picked that ball up centrally and had one thing on his mind - he wanted to hit it. It was a lucky ricochet, but to be fair to him he opted to hit it from distance and he was lucky.

"Stunning, really, because Monaco have been professional in the manner in which they have played but they haven't threatened Arsenal's goal. A sucker punch."

Image source, AFP

Now then. This has come out of nowhere as Monaco take the lead through Geoffrey Kondogbia. Danny Welbeck loses possession and the visitors attack with speed, Joao Moutinho squaring a ball to the unmarked Kondogbia, who shoots from more than 25 yards and his effort flies into the back of the net via a slight deflection off Per Mertesacker.

The deflection left the keeper with no chance.

Arsenal are at their best when they attack quickly and they have another chance as Santi Cazorla feeds a pass to the onrushing Hector Bellerin on the right, he crosses low into the area but Olivier Giroud's first time effort goes over. The Gunners are getting a little close.

Hector Bellerin is beaten for the first time by the tricky feet of Anthony Marital, who fizzes in a cross from the left that Joao Moutinho meets with a volley, but sends it high into the stands.

Former Arsenal and England centre-back Martin Keown
5 live Sport

Image source, Getty Images

"It's that man again. Sanchez can all of a sudden come alive. He cleverly checked his run and still managed to get a shot off. He had to swing his right foot at it because the ball got stuck under his feet. Sanchez always sees a way through that midfield, and his feet are so quick. He's incredible."

Even closer! This time it is a lovely flowing move with Mesut Ozil and Alexis Sanchez exchanging passes, which ends with the latter having space inside the area but he lifts his shot just over the bar with the ball a little behind him.

Phil McNulty
BBC Sport chief football writer at Emirates Stadium

"Easy to see why Monaco have such a sound defensive record. Well organised, strong in the tackle and willing to throw bodies in the way. Arsenal manager Arsene Wenger suspected this might be the way of things and the challenge for Arsenal (and their supporters) is not to let frustration get the better of them as they probe for a way through."

A shot on target! Laurent Koscielny pounces on a stray pass by Nabil Dirar on the left and races forward before shooting towards the near post, but Monaco keeper Danijel Subasic has it covered.

Former Arsenal and England centre-back Martin Keown
5 live Sport

"This is end-to-end stuff. Both teams only know one way, to soak up pressure then bomb forward."

Paul Collins: This is poor from Arsenal and exactly why we won't win the Champions League.

Rayguns Lk Rl Enough: Why is Welbeck starting ahead of Walcott? He'd struggle to hit an aircraft hangar.

Alistair Wiseman: Arsenal started well but seem to have remembered that Welbeck can't hit a barn door and Ozil's asleep.

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Half-an-hour gone and not a single shot on target as Arsenal pass the ball around patiently trying to build an attack. There is no sense of urgency from either side at the moment.