City were tearing United's fragile defence apart and Gundogan's goal was a fitting return for domination that had already brought them the lead through Kompany's header.
Now instead of a morale-boosting celebration, Pep Guardiola's side have been forced to wait to clinch their third title in seven seasons and can not be guaranteed the title even if they win at Tottenham Hotspur next Saturday.
"But when you get a chance like that to hopefully make amends and contribute a victor is a great feeling". You could see the relief after the first goal and I'm just glad to contribute'.
The immediate implication of the loss was the postponement of their title celebrations, which will surely still happen at some stage in the coming weeks with Pep Guardiola's side enjoying a 13-point lead.
"My motivation is to finish second, I still have the motivation of finishing top four, mathematically is not done, is a good distance but not done so that's the first objective but after that I don't hide", he added.
"The manager didn't have to say much at half-time as we knew ourselves as players it was a poor performance".
Luckily for their supporters it did as United followed Liverpool in beating Pep Guardiola's men in the league.More news: Facebook users should expect to pay for privacy, Sandberg says
JS: Even so, I thought that City were still worthy of a point. But as far as our intention, there are no complaints'. It's odd that City's two goals at Old Trafford came from a corner and a free kick when United are normally so organised defensively and Guardiola sides aren't particularly known for their danger from dead ball situations. They found their game, they have their spirit.
They won the first-leg 5-3 but conceded those three goals in the space of 29 minutes.
'We played with courage and created so many chances in the first half. We improve at every level but it was not enough.
"He's proven it season after season and he seems to be getting better and better".
United's record signing has attracted criticism in recent months - finding himself out of the side on occasion - and he was the subject of much of the pre-derby talk, with City boss Pep Guardiola claiming he was offered the chance to sign the France worldwide in January.
He said: 'I got the chance to congratulate City.
"Played at City, if they win they are champions against Manchester United".