The Belgian’s left-footed strike from the edge of the area proved decisive as Pep Guardiola’s men suffocated Chelsea with their intensity to move six points clear of the Premier League champions after seven games.
De Bruyne left Chelsea for Wolfsburg in January 2014 after making only a handful of appearances for the Blues and moved to City for £58million 18 months later.
“That’s the past – what happened, happened,” De Bruyne told BT Sport when asked about his time at Stamford Bridge. “I don’t regret coming here.
“It made me stronger in a lot of ways and it’s part of a career; if you are at the club you want to play more.
“I made a decision at the time, I did something that was in the best interest of me at the time (to leave), but I’m very happy with my new team, with City.”
Asked about the game, De Bruyne added: “I think we had more chances than Chelsea but just a little bit. I think tactically it was a great game and it’s a very nice win because it’s difficult to come here.
“Obviously it’s very nice for us, we know it’s just the beginning. It’s important to maintain the winning streak and win as many games as possible.
“The feeling if you win is better for all the team and everybody is excited.”
Additional reporting by the Press Association.