Schalke 04 became the first non-English team to win a European game at Arsenal in nine years as Klaas-Jan Huntelaar and Ibrahim Afellay clinched a 2-0 victory to put the Germans top of Champions League Group B on Wednesday.
Arsenal had not lost at home to foreign opposition since 2003 when Inter Milan claimed the points but their Emirates Stadium fortress looked anything but secure as they produced a woeful performance, managing just one effort on target.
They still looked like escaping with a 0-0 draw as Schalke, riding high in the Bundesliga after beating arch-rivals Borussia Dortmund at the weekend, wasted some great opportunities but Arsenal's luck finally ran out.
Dutchman Huntelaar rifled a shot past keeper Vito Mannone with 14 minutes remaining to give the Germans a deserved lead and Afellay, on loan from Barcelona, sent the boisterous away fans into party-mode with a tap-in second in the 86th minute.
Arsenal's disgruntled fans had already started heading for the exits and unless their team rediscover some form, what appeared to be a relatively easy passage to the last 16 may still become problematic with a trip to Gelsenkirchen next up on November 6.
The North London side have six points, one behind Schalke who look well-placed to take top spot with three games left.
"We seem to be lacking a bit of confidence with the ball," Arsenal's assistant manager Steve Bould, who was in charge as Arsene Wenger sat out the third and final game of a European touchline ban, told reporters.
"They are a really good side and it's a tough competition. A 0-0 would have delighted us.
"We've still got nine points to play for and I'm sure we'll perform a damn sight better next time."
Schalke boss Huub Stevens felt his side had been deserved winners.
"I was not happy with the first half, we were too cagey," he said. "We are happy with seven points, we have won two games in a row but there is a long way to go.
"In the second half we deserved to win the game. Huntelaar is Huntelaar, if he is in the box and you let him go he will get his goal."
"Arsenal are still the favourites for the group when they get some of their players back."
Arsenal did start reasonably brightly with Gervinho nearly getting a foot to a Lukas Podolski cross but the home side's confidence, rocked by a 1-0 defeat by Norwich City at the weekend, quickly drained away.
In his programme notes, Wenger described his side as having had "illusory possession" at Norwich and they again flattered to deceive in a sterile first half.
Missing the pace of the injured Theo Walcott and Alex Oxlade-Chamberlain and with Santi Cazorla struggling to impose himself in midfield, the home side hardly tested visiting keeper Lars Unnerstall before the interval.
When Schalke finally began to throw off the shackles they were by far the more threatening side.
They were unlucky not to have been awarded a penalty after 14 minutes when Afellay appeared to have his ankles clipped by Mannone as he raced into the area.
Much to the disgust of Stevens, Afellay received a yellow card for diving - a fate that also awaited Gervinho late on for a much more blatant tumble to the turf.
Peruvian Jefferson Farfan twice elected to pass rather than shoot and moments before the interval Huntelaar wasted a golden opportunity, shooting hopelessly wide of a yawning goal when set up by Atsuto Uchida's low cross.
Kicking towards their fans Schalke began the second half brightly but were guilty of more profligate finishing when Farfan cut a low pass back to captain Benedikt Howedes inside the penalty area but he scooped his shot over the crossbar.
Arsenal were hanging on as Schalke continued to threaten with Farfan finding acres of space down the right against struggling left back Andre Santos.
The Londoners sent on Olivier Giroud for Gervinho to try to grab a late winner but instead it was Schalke who made the breakthrough with 76 minutes on the clock.
Afellay's header caught the defence flat-footed and Huntelaar this time made no mistake, slamming a shot into the net to send the fans behind the goal into wild celebrations.
Victory was secured in the 86th minute when Farfan again escaped Santos down the right and provided Dutchman Afellay with an unmissable opportunity.
It completed a miserable night for Arsenal who last tasted a home defeat in the Champions League against Manchester United in the 2008/09 semi-finals.comments