The Bundesliga side secured a win over the Partenopei to reclaim control of its own Champions League destiny, with the coach particularly enthused by his back four.
Goals from Marco Reus, Jakub Blaszczykowski and Pierre-Emerick Aubameyang secured a vital three points for last season's runner-up that moved it into second in Group F, level on points with the Partenopei but, crucially, ahead of the Italians on account of a superior head-to-head record.
Given a draw would have ended BVB's hopes of reaching the last 16, Klopp was understandably thrilled with the result, particularly as he was forced to make do without a number of defensive regulars.
"It was clear it would be a spectacular match," he told Sky Deutschland. "We had a lot of chances. [Robert] Lewandowski had a great game but missed two really big chances, Miki [Henrikh Mkhitaryan] as well. [Pepe] Reina showed a good performance.
"Napoli was a really good opponent. But our back four was great. You could think Erik Durm is born for the Champions League."
Midfielder Sven Bender played on despite suffering a broken nose early on in the game and Klopp rued the Germany international's misfortune having only recently recovered full fitness.
"I hope Sven Bender will be all right very soon. It's unbelievable what bad luck he has," said Klopp.
Dortmund heads into its final group game against Olympique de Marseille knowing a win will ensure its place in the knockout phase, but Klopp warned that the Ligue 1 side will be desperate to restore some pride having lost all five of its matches to date.
"If you leave Marseille a bit of room they can play very good football," he added. "They don't want to exit the Champions League with zero points."
Kevin Grosskreutz went on to stress the importance of the win for Dortmund, given consecutive defeats against Arsenal, Wolfsburg and Bayern Munich.
"We wanted to make up for the last few games - for the city, for the club and mainly for ourselves. We did that very well. We accepted the fight and the win was deserved," he said.
"After Napoli scored their goal, I asked Sebastian Kehl if the result was still good enough for us. Our coach had explained everything yesterday [Monday], but I didn't fully understand it at the time. After we scored to make it 3-1 I knew that was enough."