The hosts looked to have laid the foundations for an important victory when Jakub Blaszczykowski scored a sensational volley at the end of a drab first half, but Stefan Reisinger made the titleholders pay for their lack of potency with an equaliser twelve minutes from time. The visitors were reduced to ten men when debutant Ivan Paurevic was shown a second yellow card towards the end, but Borussia were unable to make their man advantage count in coach Jürgen Klopp's 150th Bundesliga game as a coach.
Eye on Bayern
With Mats Hummels, Mario Götze and Ilkay Gündogan all handed the opportunity to rest, Dortmund required the opening stages to acclimatise to the new faces in the side. It was apparent that Dortmund were lacking their usual tempo, prompting inevitable suggestions they were saving themselves for Saturday's showdown with Bayern Munich.
Marco Reus lost his footing at the crucial moment when he finally did create an opening as the first half matured, but otherwise the visitors were enjoying a far easier evening than they might have expected.
Cracker from 'Kuba'
However, just as the promoted side were looking forward to taking a morale-boosting clean sheet in at the break the deadlock was broken, and in spectacular style. Lukasz Piszczek's expert cross was chested down by Blaszcykowski, who received the ball back from Kevin Großkreutz before swinging a superb right-foot volley into the very top corner of the net.
'Kuba' could have had a second shortly after the interval, but for the outstretched arms of Fortuna keeper Giefer clawing out a misdirected cross that was headed for goal. The hosts' slender lead came under threat at the other end when Robbie Kruse sprinted away, but after hesitating to shoot himself he forced the ball across to Reisinger, whose eventual finish was blocked by his own man in Ken Ilsö.
Reisinger rises highest
It was a rare threat on the champions' goal, but uncharacteristically Dortmund were still struggling to convince in attack themselves. Großkreutz, yet to score in the Bundesliga this season, went close when his placed shot skimmed over the bar from Marcel Schmelzer's pull-back, but for all their possession, it was a chance similarly seldom to those of the visitors.
Such a slender lead was always going to be dangerous and Dortmund's fears were confirmed on 78 minutes as Kruse broke away down the left for Düsseldorf. The Australian international's cross was met by the powerful Reisinger, who rose above Schmelzer to force his header past Roman Weidenfeller in the BVB goal. Großkreutz missed a sitter as the clock ticked down for Dortmund, who still couldn't find a way through even after Paurevic received his marching orders two minutes from time.
Line-ups and statistics