The match turned out to be a lot harder than City's fans had anticipated, especially after star midfielder Kevin De Bruyne went off injured. It took a Rodri goal after 68 minutes to crack Inter's resistance.
Even then City's supporters could not relax as Inter threatened to drag a tense final into extra time with goalkeeper Ederson making two superb late saves.
An eruption of joy greeted the final whistle with City's players sprinting towards their fans in the Ataturk Stadium.
"You have to be lucky ... It was written in the stars. It belongs to us," said City manager Pep Guardiola. "With this competition, the treble is so difficult."
Player ratings from the match can be seen in the picture gallery above. To view the next image, click on the arrows or swipe if on a mobile device.