The German enjoyed living life on the edge as BVB eventually ran riot against Hamburg, but revealed injury concerns ahead of the Champions League
Thorsten Fink's men could have dared to think they had secured a point when they drew level at 2-2, but were subsequently unprepared for an avalanche of goals late in the second half as the Schwarzgelben retook the initiative.
Despite admitting his side had to improve, Klopp could not stifle a smile when recalling how Dortmund took complete control of the Bundesliga tie.
"After it became 2-2 we remained quiet for a bit, but then it was outstanding. It was really fun, we were so hard to stop," grinned the 46-year-old to reporters.
"This was a step forward for us, despite the two goals. This must not happen to us, especially in the Champions League. We must take drastic action to improve the standards."
Despite the success that ensures the Ruhr outfit retain top spot in the Bundesliga, Klopp admitted his concern over the fitness of Neven Subotic and Henrikh Mkhitaryan.
"Neven took a knock to the foot in the first half but thought he could continue," he added. "We will regulate his exertions in the next days.
"Mkhitaryan received a blow to the knee. [Sven] Bender is a little bent over. I hope we can all come out of this cleanly."
Subotic and summer signing Mkhitaryan were withdrawn in the second period, but doubts still remain for Tuesday's Champions League opener against Napoli.