All the pre-match hype had been over Jurgen Klopp's "heavy metal" approach looking to again overcome Wenger's Arsenal "orchestra" as they had at the Emirates Stadium a fortnight ago.
While Klopp's well-drilled side did dominate for long spells as they looked for an eighth successive home Champions League win, having never lost against English opposition, the Germans were made to pay for not converting their chances when Ramsey nodded home a knockdown from Olivier Giroud on 62 minutes.
Wenger said: "We were light metal.
"This is a huge result.
"We had a united, focused performance, especially defensively.
"We had a lot of possession, but it was a bit sterile possession in the first half because we could not create chances.
"It was a question of being focused and intelligent, and not to make the first mistake, to wait for the moment where we could create openings in their defence. We did that.
"We had a difficult period at start of second half, but after we scored I felt we could have scored a second goal and we were less under pressure. Overall it's a huge win here.
"If you look at the results they have made at home in the Champions League, not many teams have achieved that."
Wenger continued: "We looked more stable defensively because we have experience in midfield not to lose the ball in stupid positions.
"Dortmund are especially dangerous when you lose the ball, and to counter that, you need maturity.
"If you have a very young team tonight you would be overrun and lose that game by a very high score. We look more stable defensively."
With Napoli beating Marseille, Arsenal - now unbeaten in some 15 away matches - 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.
"I have a lot of respect for Dortmund because they are a very good side," Wenger said.
"Unfortunately this group is a very strong group, and one of the big teams will have to pay a heavy price. I hope it will not be us."
Arsenal had come into the tie on the back of a 2-0 victory over Liverpool which moved them five points clear at the top of the Barclays Premier League table, and Wenger challenged his men to produce another composed display when they travel to Manchester United on Sunday.
"It just hope that is strengthens the belief of my team that we can put another great performance in," he said.
"You know we have another massive game on Sunday, and we want that kind of performance again."
Ramsey's close-range strike took the Wales midfielder's tally to an impressive 11 goals for the season in all competitions.
Wenger said: "This season he has gained confidence and he has an unbelievable engine to go from box to box. Confidence and his ability of course makes him a dangerous player.
Dortmund should have gone ahead just before the break when Henrikh Mkhitaryan shot wide from the edge of the penalty area after Arsenal were carved open down the right.
Gunners goalkeeper Wojciech Szczesny saved well from Jakub Blaszczykowski early in the second half, with Marco Reus' follow-up effort chalked out for offside.
Klopp, who guided Dortmund to the 2013 Champions League final at Wembley, feels on this evidence, Arsenal must be taken seriously.
He said: "Yes (Arsenal can win the Champions League). They are young, healthy and good technicians.
"They won a clever game tonight and could go to the final and win it - as long as they don't play against Bayern Munich."
Despite the defeat, Klopp feels Dortmund's qualification hopes remain in their own hands, with a home match against Napoli and a trip to bottom club Marseille the final two Group F fixtures.
"We had 11 shots before they scored and sometimes it was like they were defending with four legs, but football is a game of results," he said.
"It is difficult after the game, but you have to look forward.
"It is a very strong group and the positive news tonight is that two wins and we will qualify."
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