City dominated proceedings from the start, with Diego Simeone's side setting up extremely defensively from the first minute.
But despite our dominance, we couldn't find a route through a stubborn Atleti defence, seeing us go into the half-time break goalless.
Pep wrung the changes in the second-half, and it paid off immediately, with substitute Phil Foden setting up De Bruyne to cooly finish past Jan Oblak into the bottom corner, causing wild celebrations at the Etihad Stadium.
In the end, we had to settle for the one goal, but it gives us a crucial lead heading into the second leg at the Wanda Metropolitano next week.
Check out the best of the images from the Etihad via the gallery below...