The Bundesliga champions fell behind shortly before the interval when Robin van Persie found the net after sloppy play from Sebastian Kehl, but Dortmund didn't give up and Ivan Perisic eventually restored parity in the closing stages of the game.
"I think we can be satisfied because it could have been worse. Even though we didn't win the match, we were the better team for at least 85 minutes and we could have scored the first goal before Arsenal did," Hummels was quoted as saying on Uefa.com.
"We didn't, though, and so after an individual mistake – which we've had a few too many of recently – we fell behind.
"After that, we were left fighting for an equaliser for a long time until Ivan scored that extraordinary goal. For many of us, this was our first Champions League match and an unforgettable evening."
Dortmund return to domestic match action on Sunday when they take on Hannover. Their next Champions League game is the away clash against Olympique de Marseille on September 28.
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