From the jaws of victory Manchester City snatched defeat at Real Madrid as Cristiano Ronaldo put recent pouting behind him to net a last-gasp winner in what was a five-goal thriller at the Bernabeu.
There was better news for Arsenal as they opened their UEFA Champions League campaign with a hard-fought 2-1 win on their travels to Montpellier.
It looked as though Manchester City had pulled off the proverbial smash and grab job in Madrid when Aleksandar Kolarov's free-kick gave them a 2-1 advantage with just five minutes left but first Karim Benzema and then, inevitably, Ronaldo rescued what would have been another miserable night for Real Madrid in what has been a troubled campaign to date.
Both Jose Mourinho and Roberto Mancini appeared to lean on the side of caution with the sides they picked and given Real Madrid had won each of their previous 16 home games to kick-off a European campaign few would blame the latter for his reticence to go gung-ho from the off.
That said few could accuse Madrid of being negative as the stuttering Spanish champions laid siege to Joe Hart's goal but were guilty of profligacy all evening.
City's game plan was to sit, soak and counter-attack and on 69 minutes they executed a break to perfection as a typical driving run from Yaya Toure culminated in the Ivorian slipping in substitute Edin Dzeko to silence a stunned Madrid faithful with the coolest of finishes.
Marcelo showed his misfiring team-mates how to get the job done when his bending effort, via a slight deflection, beat Hart to earn Madrid a deserved leveller.
With five minutes left though it looked as though Kolarov's free-kick, which evaded everyone in a packed box, might just earn City the most memorable of victories. Real substitute Benzema had other ideas when he turned smartly on the edge of the area to beat Hart with a low drive on 87 minutes to draw Madrid level.
It was left then for Ronaldo to cement his status as a pantomime villain in the blue side of Manchester when in the final minute he cut inside to earn Madrid the most unlikely of winners with a daisy-cutter that Hart may feel he should have done better with.
Polish hit-man Robert Lewandowski left it late for Borussia Dortmund but it was his 87th minute effort that gave the German outfit a winning start at home to Ajax in their Group D opener.
Montpellier found Arsenal's Thomas Vermaelen to be in a charitable mood as he gifted them an ninth minute opener on their Champions League bow. The Belgian's clumsy challenge invited Younes Belhanda to go over in the box and from the resultant spot-kick the Montpellier man dusted himself down to register with a Panenka penalty of impish elegance.
To date though this term Arsenal have shown none of the brittleness that has defined bygone campaigns and within ten minutes they were not just level but ahead. It was lead they would keep.
First the much maligned Olivier Giroud reminded his former employers of what they've been missing in what has been a sluggish start to their defence of a surprise Ligue 1 title last term, as his cute lay-off played in Lukas Podolski to nonchalantly stroke the ball past Geoffrey Jourdren.
The rangy front man was also involved in Arsenal's second as he played in Carl Jenkinson down the right to whip in a low centre that a rejuvenated Gervinho finished with minimum fuss from close range.
After the interval Montpellier rallied and went close to finding a leveller when Remi Cabella lobbed a superb effort onto Vito Mannone's bar, while later Belhanda shot straight into the throat of Arsenal's goalkeeper when he should have dispatched.
In Group B's other fixture Schalke also picked up a maximum haul away from home as Klaas-Jan Huntelaar did what he does best, in grabbing a second half winner at Olympiakos to earn a 2-1 victory.
Malaga's debut in Europe's premier club competition went decidedly better than Montpellier's as they continued their excellent start to the season with a comfortable win over Zenit St Petersburg.
Isco got Manuel Pellegrini's men off to a dream start as he registered in just the third minute before Javier Saviola cemented their supremacy with a second before half-time. It was left to the impressive Isco to put the gloss on a polished display when his second of the evening secured a 3-0 victory for the Spanish outfit.
At the San Siro it proved to be a night of frustration for AC Milan as Anderlecht came away from their trip to the Italian giants with a noticeable goalless stalemate.
Paris Saint Germain got their European campaign off to the proverbial flyer as they eased past Dynamo Kiev 4-1 in the French capital. Zlatan Ibrahimovic got them on their way as he became the first player to score for six different clubs in the Champions League, before Thiago Silva and Alex put them in cruise control before half-time.
Zenit briefly rallied when Miguel Veloso bagged his side a consolation but it was left to Argentine schemer Javier Pastore to have the final say for PSG in injury-time.
In Group A's other clash Porto were too good for Dinamo Zagreb as they won comfortably on their travels. Lucho got them on their way before Steven Defour made sure of the points in the final minute.