No one thought Manchester City would conquer Europe in just a year or two but it has been a very brutal learning curve for them and it capped the whole mad business of last night that Mario Balotelli, of all people, should be the one finding the required moment of composure and making all that baggage he carries around suddenly worth the bother.
The sheer pummelling Roberto Mancini's side underwent at the hands of the wonderfully gifted German champions made them unworthy of the late draw they secured through a penalty, converted two minutes from time by Balotelli – the man who just never misses.
The Germans punched huge holes in City's defence all night and it took one of the finest goalkeeping displays on these shores in years – eight great saves by Joe Hart at the final count - to preserve a place in the tournament which had seemed utterly lost, as the clock ticked down.
Perhaps City have grounds to feel it was time for that little slice of luck where the Europe journey is concerned. After last year's formidable group and last month's engagement against Real Madrid in the Bernabeu, they were hit by an express train in the standard of Jürgen Klopp's players last night whose daring high line and intensity to drive at them, again and again, was beyond the realm of expectation.
In Mario Götze, Marco Reus, Sven Bender and Ilkay Gundogan, Klopp has a group of players who can cause a lot of trouble to some very good sides.
Hart may never again match his display, which dwarfed even his first-half performance in Madrid, and it was enough to have made the night a rather punishing one for the Manchester United manager, Sir Alex Ferguson, a spectator, who decided against paying Shrewsbury Town £100,000 for him six years ago.
The rest of the City side – languid, casual, outwitted for long periods and often harried out of possession – did no less damage to their own manager. Mancini's team managed ten points in the Champions League and still went out last season and on the basis of what we have now seen qualification still looks like a very tall order.
Two wins, home and away, against the Dutch champions Ajax seems like a minimum requirement and beyond that they will probably need to win either the return game against Real or their a trip to Dortmund's Westfalenstadion in their final assignment of an unforgiving group.
They will need to discover disciplines which have not been there if they are to make themselves a force in this competition at the second attempt.
There were grounds for encouragement in the first-half display by David Silva. His architecture of City's excellent opening half hour was one of his finest expositions of football in a City shirt and returned us to his heights of last autumn.
City could have been three goals clear in that early period, each of the chances delicately furnished by Silva – the lofted a ball over Neven Subotic, the carved pass inside a central defender. Twice the goalkeeper, Roman Weidenfeller, prevented Sergio Aguero seizing those opportunities. On the third occasion, Pablo Zabaleta's wild finishing did the job for him. Hart and Weidenfeller were matching each other, save for save, at that stage in one of the most thrilling, open first halves of football that this year's Champions League tournament will offer. Its most extraordinary aspect was the half-time deadlock – testament to those two goalkeepers' displays.
Mancini rued the poor finishing but the deeper cause for concern was the way that City's game began to fray. There was carelessness in possession – from Silva and particularly Yaya Touré, whose wretched night was so unusual and inexplicable that the assumption put to Mancini was that he must be injured. He wasn't.
Dortmund , with their risky high line were always well set to pounce and exploit the errors and then to press home their advantage. The Italian offered one of his inscrutable explanations for the failings last night. "It is my problem. I will solve this problem," he said, laughing. But the defensive challenge just looked too much for Mancini's players, who have conceded 16 goals in nine games.
Matija Nastasic is the preferred central defensive option for the big games, because he Mancini feels Joleon Lescott lacks mobility. But the Serbian exuded less and less security as the Germans pushed City further and further back. The loss of Javi Garcia to a thigh injury just after the half hour didn't help.
Silva finished the first half squandering the best chance of the lot, managing to volley a Zabaleta cross sky high. But the backlash came quickly. Touré's slackness in possession allowed Ilkay Gundogan a last blast before the interval and though Mancini chopped and changed – going from a four-man defence to three to four again and introducing the rigour of Aleksandar Kolarov – Jack Rodwell was hussled into attempting a pass across his back line without looking and Marco Reus pounced. The striker sped away to finish with a shot which Hart pushed out a despairing hand to, but which he couldn't keep out. Dortmund ought to have had the game finished 16 minutes later when another Touré error culminated in a point blank chance for Robert Lewandowski, who fired wide.
Substitute Balotelli's header from Zabaleta's cross four minutes from time was clawed away by Weidenfeller and then came salvation, when Aguero's volleyed cross struck Neven Subotic's arm. It was marginal, Subotic later complained bitterly and the defender certainly couldn't have avoided a ball struck at him from such close range. But it bought the opportunity which Balotelli took, with usual insouciance. Building upon it is the formidable part.
City slacker: Rodwell's gaffs
Jack Rodwell has only played 311 minutes since his £15m transfer from Everton but has already been directly responsible for City conceding three goals.
On his City debut, on 19 August, the 21-year-old gave the ball away allowing Southampton to counter attack sharply and for Steven Davis to score. A week later, Rodwell handled the ball to concede a free-kick which Liverpool's Luis Suarez put in. And last night Rodwell passed the ball straight to Marco Reus to give Borussia Dortmund the lead.
Man of the match Hart.
Match rating 9/10.
Referee P Kralovec (Cz Rep).