The German coach highlighted the steady progress his champions are making as a team after their last-gasp victory over the Dutch
The German champions controlled the second half and their probing was eventually rewarded, to the relief of their coach.
"It was an amazing and very intense match," Klopp told reporters after the game.
"We defended well for 90 minutes and created opportunities again. The team has been progressing for a while and we are continuously developing.
"There are still a few things we can do much better but we are very satisfied and will continue working."
Dortmund travel to Eastlands to face Manchester City in the next round of Champions League fixtures, while Ajax host Group C leaders Real Madrid.