Midfielder Aaron Ramsey hailed a classic European away display as Arsenal beat last season's Champions League runners-up Borussia Dortmund in Germany.
The Gunners became the first English side to win in the Westfalenstadion after the Wales international continued his run of form with the only goal in the 62nd minute.
"It was a great achievement from the lads," Ramsey said.
"It is always a difficult place to come.
"We realise that from the last time we came here and drew 1-1.
"They got to the final last year and were unlucky and they are a strong team so we had to do our defensive work.
"We were very good defensively even thought we didn't have any shots in the first half and they had a few, even if it was from distance.
"We kept our shape really well, we were patient and it was a proper away performance from the lads and we got them on the counter-attack."
On his own goalscoring run after an 11th goal of the season Ramsey added: "I am enjoying myself at the moment and everything seems to be going in.
"I'm delighted with the way I'm playing and the goals I'm scoring."
Manager Arsene Wenger was impressed with a mature display from his side.
"We were under consistent pressure from the first to the last minute and we didn't make mistakes," he said.
"It was a very tight game, very difficult, but we were united and had a compact block which didn't give them room to create chances.
"We knew at half-time it was a question of keeping our team focus without making a mistake and letting our technical superiority come in at some stage of the game.
"We came into the game and suddenly we looked like we could score.
"I was concerned it was a long time to go when we scored but after that we created chances and could've scored a second goal and they (Dortmund) tired a little bit as well.
"We looked stable defensively. We were under pressure but we had a good mixture of technical awareness and attitude.
"Overall it was a very mature performance."
On Ramsey he added: "A year ago I thought it would be difficult for him to score but he is a young player and is confident and has improved tremendously – which is a huge credit to him."
Dortmund had come into the Group F encounter searching for an eighth successive home Champions League win and had never lost against English opposition.
Jurgen Klopp's well-drilled side, who had won 2-1 in London a fortnight ago, dominated for long spells, but were made to pay for not converting their chances when Ramsey nodded home a knockdown from Olivier Giroud on 62 minutes.
It may not have been the flowing display which Wenger would have preferred – but the Barclays Premier League leaders once again answered questions with a display of real character to hand a rare defeat to last season's beaten finalists.
With Napoli beating Marseille, Arsenal still have work to do to secure safe passage through to the knockout stages, but will have gained more belief they can last the distance this season.
Totally against the run of play, Arsenal found themselves ahead on 62 minutes.
Mesut Ozil, who had done little all night, collected the ball on the edge of the Dortmund area and clipped a lovely cross over for Giroud.
The France forward showed great strength to cushion a header down, and Ramsey bundled the ball past Roman Weidenfeller.
Even if the Gunners beat bottom side Marseille at the Emirates on November 26, they could still need to pick up a point at Napoli in their final group game in order to secure their progress.