No one thought Manchester City would conquer Europe in a year or two but it has been a very brutal learning curve and last night, just when it seemed that the whole adventure had collapsed before it had started once again, came the moment when Mario Balotelli made all his baggage worth carrying.
The raw pummelling that 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 a minute from time by substitute Balotelli, the man who just never misses.
The Germans had punched huge holes in City's defence all night and it took one of the finest goalkeeping displays on these shores for in years by Joe Hart, including eight sublime saves, to keep them at bay.
Early on City had looked as if a year in Europe had educated them a little, as they set off in the rain-leaden night. This was a fluent, incisive City, immediately stringing together rapid passes in one of the most thrilling first halves of football that this year's tournament will see.
Its most extraordinary aspect was the goalless half-time scoreline and that much was testament to two sublime displays of goalkeeping. Hart's five saves in that period eclipsed even his first-half display at the Bernabeu. Roman Weidenfeller matched him, denying Sergio Aguero what might have been a hat-trick of his own.
But there was carelessness in City's breakneck speed and Dortmund, with their risky high line, were always well set to pounce and exploit it. David Silva was profligate on several occasions and so, too, Yaya Touré, on an unusually ponderous night by his standards.
But on 62 minutes a loose pass proved fatal. Jack Rodwell, whose 33rd minute arrival was forced when Javi Garcia limped off, attempted a pass across his back line without looking and Marco Reus pounced, speeding away to finish with a shot which Hart got a despairing hand to but could not keep out.
Balotelli came on and his header from Pablo Zabaleta's cross was clawed away by Weidenfeller. Then came salvation – Aguero's volleyed cross struck Neven Subotic's arm. It was marginal. The defender could not have avoided a ball hit at him from such a distance.
But with the succession of European opposition they have faced, City arguably deserved their break. Now they must learn to capitalise on it.