Assistant referee Stefan Johannesson is Arsenal’s biggest Swedish hero since Freddie Ljungberg

For a Swede, a nation not exactly renowned for its rip-roaring sense of humour, Stefan Johannesson must love the banter. When he returns home to Stockholm on Friday to settle down with an enticing smorgasbord and perhaps a few tasty Scandinavian ales, he can regale his friends and relatives with tales of how he became an unlikely Arsenal hero for the night.

After years and years of players, pundits and punters wondering exactly what those officials do next to the goal, apart from warding off rigor mortis, we found out in some truly ludicrous scenes at the Emirates Stadium on Thursday evening via the bold Stefan.

An unconvincing Arsenal were trailing 1-0 to Milan after 39 minutes of a Europa League last-16 second leg suddenly more taut than Alexis Sanchez's piano wires. Their Europa League quarter-final place was very much on the line holding a 2-1 aggregate lead before Johannesson decided to do Arsenal a solid.

As Danny Welbeck fell over with the visiting defender Ricardo Rodriguez doing no more than shadowing the Arsenal striker, a goal kick seemed the only sane call. Welbeck had taken a tumble before turning hopefully in the direction of the bearded bloke standing next to him.

Which was to prove a better decision than his dive as the referee Jonas Eriksson also took leave of his senses. First he analysed the situation, then he consulted his theatrical compatriot Johannesson, who decided to thrust himself into the limelight with more than a touch of farce.

He was quite adamant that Rodriguez had fouled Welbeck, and the penalty was awarded. There was bedlam among the protesting Milan players.

Rightly so when you studied the replays to realise Arsenal FanTV wouldn’t have made a case for Welbeck, whose dive had more stages than the Tour de France. It was one of the worst calls you will see in any football match in any year before Welbeck mishit the penalty yet still sent Gianluigi Donnarumma the wrong way.

It was a sore one for Milan to stomach, a cruel and bitter blow that changed the nature of the tie.

Little wonder their impressive manager Gennaro Gattuso, a World Cup winner who looks like he would be tastier than the finest risotto in a bare-knuckle boxing bout, rounded on Johannesson at half-time.

Milan and their vibrant posse of visiting fans had been bouncing courtesy of Hakan Calhanoglu unleashing a shot from distance that somehow managed to elude David Ospina on 35 minutes, but the momentum was sucked from them in one fateful moment.

It was the best Swedish intervention to visit Arsenal since Freddie Ljungberg rocked up in North London two decades ago.

To add insult to injury, the 19-year-old Donnarumma somehow managed to spill a tepid Granit Xhaka effort as Arsenal moved 2-1 clear on 71 minutes.

With Milan huffing and puffing but their purpose largely snuffed out, Welbeck added Arsenal’s third with a simple header to complete a 5-1 aggregate victory that looked improbable prior to the penalty that should never have been.

Nobody is suggesting Arsenal did not deserve to progress over the two legs. It is just their progression was sullied by outside influences.

"The referee was man of the match. I will never forget that," said Calhanoglu. "We played well and it's not easy to do that here. We scored and then conceded an incredible goal, it's not normal in the Europa League to see something like that..it's obvious that was the incident that changed the game."

It is better being lucky than good as they say. And the winner takes it all as Abba sung, but perhaps sickened Milan diehards will want to avoid all things from IKEA for a while after being on the receiving end of some shoddy goods from Sweden. The only misfortune to hit Arsenal was losing Laurent Koscielny early on to a back injury.

With opportunity there to be seized upon, Arsenal could yet win this gloriously maligned trophy in Lyon in May as Arsene Wenger remarkably moves within three victories of a first European title at the club since his appointment in 1996.

It would be ironic in the extreme if such incredible fortune visited the French martinet after such miserable domestic happenings.

He looked on the verge of a broad grin when asked about the penalty decision, perhaps recalling his thoughts from a month ago when he said English players were now "the masters of diving".

Welbeck - recalled to the England squad earlier in the day - wouldn't win a BAFTA for his turn, but it was a timely cameo in the bigger picture.

It seems like somebody up there must like Arsenal. Such gifts from the gods must be gratefully received while they are going.

If the Europa League was good enough for Jose Mourinho last year as part of his eccentrically self-proclaimed treble at United, it is certainly good enough for Wenger this time.