Pride came before the fall.

Arsenal will this week dust themselves off and look around to make sure they have not tumbled too far, the London club having suffered defeat in the Champions League and found themselves in a three-way fight to reach the last 16. They have landed in that situation with a bump since they had returned to European competition feeling pretty good about themselves and on the back of a 12-match unbeaten run.

They were tripped up by Borussia Dortmund - the Germans scoring twice at the Emirates to maintain traction on their ambitions of escaping Group F. Dortmund lost last season's final and were not as persuasive on Tuesday, yet they cured any Arsenal supporter experiencing giddiness after the club had marched to the top of the Barclays Premier League and Champions League group.

Fans had been cooing at the craft shown by their side as Arsenal constructed a scintillating opening goal against Norwich City; Jack Wilshere finishing a routine of swift, one-touch passes. The visit of Dortmund was far more a test of Arsenal's resolve and the Germans were in little mood to stand and watch Arsene Wenger's side go through their repertoire - stifling their hosts for long periods but still managed to play high up the pitch, forcing the likes of Mesut Oezil into the sort of spaces that would cause you to feel claustrophobic. Olivier Giroud had equalised after Henrikh Mkhitaryan's opener, but Arsenal often seemed vulnerable.

It was only when Santi Cazorla replaced Wilshere after an hour that Arsenal began to find more room but Robert Lewandowski's volley after 82 minutes ensured that Dortmund returned home well-fed on three points.

"Technically we have met some good teams this season but physically they were stronger than many other teams that we have met," said Wenger. "Dortmund were well organised to stop us from playing and we put ourselves on the back foot with the first goal and were naive for the second goal."

If Arsenal's eyes are now open to the challenge of reaching the next phase of the competition, Juergen Klopp caught sight of a Dortmund team of greater maturity. The German side's head coach looked on from the stand as he serves a two-match suspension in European competition but was able to put his feet up confident in the knowledge that his players have grown into a formidable force.

"The way we played those last minutes was just outstanding," said Klopp. "The team showed extreme maturity. The whole performance was very mature. We don't think about how we are a top team but how we can beat a top team. Arsenal had the better chances but we did not come to dominate; we came for a result."

Dortmund were not at their most irresistible in attack but there was evidence the youthful enthusiasm which drove them on last term has been substituted with a more methodical approach. It has had the effect of allowing the Germans to appear less flustered and harder to unnerve. "We had what felt like three shots and we scored two goals," added Klopp. "The biggest development for my team was that we hit them late on and now are back in the race."