After a goalless opening 45 minutes against Aston Villa, the Champions struck within a minute of the restart, through Raheem Sterling’s 13th goal of the season.
The hosts went on to score twice more with Gundogan adding the third with a beautifully-struck half-volley to effectively kill the contest - and the German asserts the timing of the opening strike provided the lift Pep Guardiola’s men needed to gain control.
“We always feel when we’re able to score the first goal or an early goal, we feel like we are unstoppable,” he stated.
“At half-time, the manager wanted us all to step forward. We created some chances in the first half but it was obvious there was something missing.
“He mentioned that in the dressing room and it helped a lot that we scored within a minute and then went on to get the second as well.
“It was a bit about patience – we could have done better in the first half but the second half was really good.”
City doubled the advantage with a controversial goal, as Kevin De Bruyne’s whipped delivery evaded everyone to curl into the back of the net.
There had been a suggestion David Silva had converted with the slightest touch but the effort was awarded to the Belgian after the game.
Gundogan laughed that he was not aware whose was the final touch – but that it did not matter.
“I actually have no idea!” he conceded. “I didn’t even see the goal!
“I just thought it was deflected and I didn’t know whether it hit David or a defender.
“I’ll have to review it!”
City’s fine second half display was marred only by a second yellow card for Fernandinho, who will now serve a suspension.
With the Brazilian deputising at centre-back with City having suffered injuries in the defensive backline, Gundogan admitted the red card could not have come at a worse time but insists the Champions will be able to cope – even if the German himself has to fill in!
“Fortunately, we still have Nicolas Otamendi, who was not able to come on because we had already changed three players.
“If I’m needed, I’m ready to help the team wherever. If I’m needed to play at centre-back for many games, I will try my best to help the team but I don’t think it’s that far yet.
“We’re unlucky at the moment and the red card doesn’t help but we’ll still have a great team on the pitch.”