Arsenal: 5 things we learned at Emirates defeat

1 Mikhi puts Özil in the shade to fill Dortmund’s post-Götze void

For all the excitement about Mesut Özil, the most creative player on the pitch was the opposition No 10 – Henrikh Mkhitaryan. Liverpool tried to sign him from Shakhtar Donetsk this summer and he showed exactly why, with a display of brilliant movement, imagination and touch. Of course ‘Mikhi’ put Dortmund ahead after 16 minutes with a clever disguised finish but almost everything he did was classy, dropping into spaces to take the ball, turning away from Arsenal players, winning free-kicks and masterfully orchestrating Dortmund’s play. Dortmund may have lost Mario Götze but they have certainly not lost their spark.

2 Özil is a genius but flawed when it comes to defending

Mesut Özil is brilliant, not that it needs to be said, but Arsenal must have realised last night that he presents slight problems in terms of his defensive work. He spent the first half in the hole, but was slightly ineffectual, both with the ball and when it came to harassing the influential Sven Bender and Nuri Sahin. So in the second half Ozil was almost moved into a Theo Walcott position – high up and on the right. That allowed Jack Wilshere and Aaron Ramsey more central roles, stifling Dortmund for much of the second half and re-establishing some control.

3 Koscielny kept Lewandowski quiet ... until the winner

Laurent Koscielny must have thought he had done a good job stifling Robert Lewandowski. The Polish striker was immaculate all night in his touch and movement, but after laying up Mkhitaryan’s opening goal he was shackled by Koscielny, a master of picking the right moment to dart forward and steal the ball – an area where Thomas Vermaelen is over-enthusiastic. Lewandowski was reduced to throwing elbows, with one on Koscielny resulted in a booking. But you can never count out a striker of Lewandowski’s ruthless instincts, and he was there with seven minutes left to win Dortmund the game.

4 The jury is out after Arsenal’s first real test of the season

It was performances against the big teams which were missing from the analysis of whether this good Arsenal start to the season could be converted into trophies. The fixture list has been generous to them so far, even their home wins against Tottenham and Napoli coming against non-performances. Dortmund, by a distance, are the best team Arsenal have faced this season. So what did Arsenal show us? They were outplayed for much of the first half, and dominated most of the second without being able to go ahead, before they were caught out. Judgement has to be suspended.

5 Arteta is now nearing his best and showing his importance

Given the recent excellence of Aaron Ramsey and Mathieu Flamini, it is easy to forget how important Mikel Arteta is. This was his fifth start since return from injury and his best yet. Arteta, in the absence of Flamini, was ferocious in defence, charging in to deny Sahin, Mkhitaryan, Marco Reus and the rest the time they needed in the first half. As Arsenal grew back into the game, Arteta was always there to show for the ball.