City took control of their Champions League round-of-16 tie with an outstanding victory in Spain, as they came back from a goal down to win through Gabriel Jesus' header and a De Bruyne penalty.
But much of the post-match focus has not been on their superb display, but instead on their manager’s masterclass as Pep did a number on Real boss Zinedine Zidane in their first ever competitive meeting as managers.
Guardiola completely baffled us with his line-up on Wednesday night, as he left out key trio Sergio Aguero, Raheem Sterling and Fernandinho from his starting line-up.
And what appeared to be a now-conventional 4-3-3 shape, with Jesus spearheading the attack, turned out to be a traditional 4-4-2, but there was nothing traditional about his tactics.
Rodrigo and Gundogan were in central midfield, Jesus and Mahrez on the wings and De Bruyne and Bernardo Silva up front.
And it had the desired effect as Real Madrid just didn't know how to handle Man City, as their midfielders, wingers and false strikers all interchanged passes and set up rapid attacks.
Following the match, De Bruyne said: "I think in the four years we are here with Pep we had some surprises and even the players, they don't really know until the game starts what we need to do.
"This is a really good start for us. Our response [to Isco's opening goal] was brilliant. Now we have the Carabao Cup final against Aston Villa on Sunday and we have to be ready."
Asked if his set-up was the 'perfect tactical plan' for City at the Bernabeu, Guardiola told BT Sport: "Yeah, but only because we won, otherwise it wouldn't count!
"They press so high and we saw that, the central defenders they are able to jam and then the space is on the outside.
"Gabriel is so quick and Riyad can do it, and in the end we know that in the last 20 minutes Raheem is so fast too, so yeah, it was good.
"We talked about trying to come here and win and we did it, here in this stadium. But it's only the first part, it's not three points and if one team can overcome this situation, it's real Madrid.
"But of course it's a good result."
Kevin De Bruyne has revealed that even the Manchester City players were 'surprised' by Pep Guardiola's tactics in their 2-1 win at Real Madrid.