Weapons store supervisor Arsene Wenger said his side were self-satisfied as they survived a gigantic terrify against Swedish minnows Ostersunds FK to guarantee a place in the last 16 of the Europa League.
The Gunners won the principal leg 3-0 yet one of football's incredible stuns looked conceivable at half-time after the guests struck two objectives in 70 seconds.
Graham Potter's side, who have ascended from Sweden's fourth level since 2010, were on top in the primary half and drove 2-0 on account of Calum Chambers' own particular objective - redirecting in Hosam Aiesh's shot - and Ken Sema's clinical strike.
Be that as it may, the Gunners - who named a sensibly solid side just three days before their Carabao Cup last with Manchester City - enhanced marginally after the break and Sead Kolasinac completed from Hector Bellerin's cross to assuage the feeling of fear inside Emirates Stadium.
"We were not at the races in the primary half," said Wenger, who saw his side booed off at half-time and full-time.
"I think in the second half it was greatly improved and we ought to have scored a couple of objectives.
"In the principal half we were stuck in an unfortunate situation and in risk since we were self-satisfied, not engaged and were open each time we lost the ball. We had no thoughts with the ball and that is the reason we were in a bad position.
"We reacted extremely well since we did the activity to qualify, however that is the thing that we need to take from the night and there's nothing more to it."
Arms stockpile, who have never won the Uefa Cup or Europa League, will find their last-16 rivals at 12:00 GMT on Friday.
Ostersund are just the second group to win a diversion at the Emirates in the Gunners' last 28 matches - a run going back to March 2017.
Wenger rolled out just three improvements from the primary leg and the Frenchman demanded the amusement was "not a convention".
Be that as it may, even with 21 years' involvement with the club, without a doubt even he didn't predict what was to come in the primary half, with the hosts looking shell-stunned and Ostersund completely meriting the lead.
Chambers was ostensibly to blame for the two strikes. For the main, he turned home Aiesh's shot and for the second he was beaten to the ball by Sema and after that got some distance from the winger's wonderful wrap up.
Things showed signs of improvement in the second half, in spite of the fact that had they deteriorated this would most likely have gone down as Wenger's least point as Arsenal manager.
Granit Xhaka supplanted youthful midfielder Ainsley Maitland-Niles at the break and the Gunners looked sensibly agreeable once Kolasinac exploited Ronald Mukiibi's air-kick from Bellerin's cross to lash home.
Danny Welbeck had four opportunities to score, yet he headed two directly at Aly Keita, chipped the other to the goalkeeper and shot directly at him again in the latest possible time.
Welbeck's endeavors encapsulated a poor night for the hosts, and on this confirmation these players won't have given Wenger any choice issues for Sunday's EFL Cup last at Wembley.
Weapons store's 15 potential adversaries in next round
Air conditioning Milan, Athletic Bilbao, Atletico Madrid, Borussia Dortmund, CSKA Moscow, Dynamo Kiev, Lazio, Lokomotiv Moscow, Lyon, Marseille, RB Leipzig, Red Bull Salzburg, Sporting Lisbon, Viktoria Plzen, Zenit St Petersburg
"We arranged legitimately and genuinely," said Wenger. "In any case, you have outer conditions, for example, the reality we won 3-0, the way that we have another defining moment on Sunday, the way that individuals intuitively think you simply need to swing up to win. Football doesn't work that way.
Ostersund may be out - yet a 14-amusement make a big appearance European crusade finishing in a triumph at Arsenal is a story for the ages.
For a group who have not played an association amusement since November - the Swedish class is a mid year occasion - they hinted at no corrosion.
Their exceptional story has been told commonly this season: since Englishman Potter's arrangement in 2010, they have ascended from the fourth level to win last season's Swedish Cup and fit the bill for Europe.
Potter said before the diversion they required a "marvel" and following 23 minutes, it resembled a veritable plausibility.
Jamie Hopcutt, whose last English club was Tadcaster Albion, had an early shot blocked and Sema constrained a spare from David Ospina at his close post.
Their fans were all the while commending the opening objective, maybe somewhat cruelly detracted from Aiesh and regarded a possess objective, when Sema crushed home their second. Saman Ghoddos - applauded by Wenger after the primary leg - helped set up the two objectives.
Curtis Edwards, another previous English non-group player, shot wide from 30 yards and Ghoddos had a free-kick spared by Ospina as they pushed for a total equalizer.
The fantasy was for all intents and purposes finished after Kolasinac's strike however their heads did not drop - they continued onward despite everything they had opportunities to score once more.
They completed fifth in the 2017 Swedish association, not sufficient for European capability, but rather they can at present return on the off chance that they win the Swedish Cup, which keeps running from the late spring until the spring.
Potter likewise joins a select club as just the 6th English director to win a diversion at the Emirates, alongside Alan Curbishley, Phil Brown, Harry Redknapp, Michael Appleton and Garry Monk.
'Barely shy of the marvel'
Ostersunds FK supervisor Graham Potter, addressing BT Sport: "I am, exceptionally pleased with the players and the supporters. To play in the way we did I felt we demonstrated genuine boldness and fortitude and played some great football against a best group.
"At 2-0 we thought we had a possibility. We played well, won however it was barely shy of the wonder.
"Aside from the initial 20 minutes at home we ran toe-to-toe with Arsenal which is no mean accomplishment considering where we have originated from.
"It is a learning knowledge we have been having. It was the first occasion when we were playing in the last 32. Through the span of the diversion we have indicated what we are about and what we are attempting to do. Today is a day to be glad for what we did over the two matches."
Details - 33% of Arsenal claim objectives are from Chambers
Regardless of advancing into the following round, Arsenal have now lost every one of their last six home recreations in the knockout rounds of European rivalry.
Arms stockpile's protectors have contributed 20 objectives in all rivalries this season, the greater part of any Premier League side (Chelsea 16, Man City 10).
The Gunners have yielded in every one of their last six at the Emirates in all rivalries; their longest keep running without a perfect sheet there since May 2014 (seven continuous amusements).
Ostersunds FK are the principal Swedish side to win an away European match in England since Osters IF beat Tottenham Hotspur in the 1995 Intertoto Cup.
Arms stockpile have scored nine claim objectives since Calum Chambers appeared for them in August 2014 - he has been in charge of 33% of them (three).
