Arsenal 3 AC Milan 1 (5-1 agg): Danny Welbeck and Granit Xhaka goals book Gunners a place in the Europa League quarter-finals

THEY profited from a dodgy Danny Welbeck dive, a  horrendous goalkeeping error and several heart-in-mouth moments in defence.

But Arsenal’s Europa League run continues in to the last eight and maybe, just maybe, Arsene Wenger could be afforded a fond farewell at a European final in his homeland.

Although, you know Wenger. Win this thing and he’ll surely have a good go at trying to persuade Stan Kroenke ’n  Co that he remains the best man for Arsenal’s future.

They do this, Arsenal, frequently lurching between Armageddon and cautious optimism in the space of ten days or so.

The crowd was healthy — for once, the official gate figure of 58,973 was not a ludicrous charade — and Arsenal were not overly complacent after their 2-0 victory in the San Siro last week.

Milan are no longer among the European elite but theirs was still a decent scalp for a Gunners side ridden with crisis before this tie began.

Few here want Wenger to stay but only the coldest of hearts would begrudge him a final in Lyon in May.

There is still plenty of European royalty in their way in a strong Europa field, but  they can go into today’s  draw with a certain degree  of hope.

Milan were rightly enraged by Welbeck’s dive to win a penalty he converted himself, to swiftly equalise following  Hakan Calhanoglu’s opener.

And their much-trumpeted young keeper Ginaluigi Donnarumma chucked one in from a hopeful Granit Xhaka effort before Welbeck headed his second to put the tin lid on a frustrating night for the Italians.

And so, a couple of weeks after that latest Armageddon,  Arsenal are the only London club left in Europe.

After three successive home matches at which the Emirates was half-empty — or half-full if you’re as positive as Wenger — the place was far fuller.

While many neutrals might have considered it a dead rubber after Arsenal’s first-leg victory, this lot know through the grim experience of the second half of Wenger’s reign that no chicken should ever be counted.

The early signs were, as expected, that this could be an uncomfortable night for Wenger’s men.

Within a minute the former Liverpool striker Fabio Borini, now playing at right-back for Milan, surged down the flank and squared for Andre Silva to thud one into the side-netting.

And after ten minutes there really was a panic on when Laurent Koscielny limped off after taking a whack in the back and was replaced by Callum Chambers.

Yet Arsenal settled into a decent pattern – plenty of pleasant pinging around from Mesut Ozil, Henrikh Mkhitaryan, Aaron Ramsey and Jack Wilshere, who was celebrating an England recall which had seemed a remote possibility just a few months ago.

And when Arsenal broke swiftly midway through the first half, Welbeck’s shot was well saved by the legs of Milan’s young keeper Donnarumma.

But just when you began to wonder whether might stroll it, Milan took the lead on the night with a bolt from the blue.

Ricardo Rodriguez fed Calhanoglu, who took a step inside and let rip from 25 yards, beating David Ospina, who might have reacted quicker, though it was belting shot.

The alarm only lasted for a couple of minutes, however, as Arsenal levelled in controversial style.

As Welbeck chased down in the inside-right channel, Rodriguez did little more than brush an arm across his chest, the England man reacting as if cut down by heavy artillery.

Ref Jonas Eriksson did not look interested but his additional assistant ref – a Pep Guardiola lookalike loping around behind the goal, indicated a penalty.

Sometimes these spare officials seem to feel the need to justify their existence and this was a glaring example.

And Donnarumma, in particular, went absolutely ballistic at the official, earning himself a booking.

But the keeper was unable to provide justice as Welbeck sent him the wrong way from the spot.

It was Welbeck’s first European goal since 2014, so England supporters might not have been too taken with the idea that the Arsenal man had made Gareth Southgate’s squad earlier in the day.

Milan were enraged again soon after when a penalty shout for handball against Chambers was turned down but that would have been even harsher than the one which had gone against the Italians.

Wilshere then tested Donnarumma, who pushed out his shot at full stretch.

And after break the keeper was at it again, denying Mkhitaryan after a sweeping cross-field move.

After Patrick Cutrone volleyed wide, the visitors became increasingly tetchy.

Suso was booked for diving – though his wasn’t as bad as Welbeck’s effort – and boss Gennaro Gattuso got into bother for thudding the ball into Nacho Monreal’s face when it went out for a throw.

But when Xhaka shot speculatively from outside the area, Donnarumma had an absolute shocker, shovelling it into his own net.

And then Welbeck nodded home from close range after Ramsey’s header had been saved to offer the scoreline a generous look.