Rooney's tally, just his sixth of the season for the Red Devils, came off a cross from Nani on the right wing and cleanly beat City goalkeeper Joe Hart to give first-place United a huge three points at Old Trafford just one week removed from their first Premiership loss of the season to lowly Wolverhampton.
"I think so," the 25-year-old Rooney told Sky Sports when asked if it was the best goal of his career. "I saw it come into the box and thought, 'Why not?' Thankfully it finished up in the top corner.
"I was trying to get in a good position for when Nani crossed it. Nine times out of ten they go over the crossbar. Today it ended up in the top corner. It is instinct. You don't have time to think about it."
Asked when he had last scored with an overhead, bicycle kick, Rooney replied: "In school I think. It's the first one since I started playing professionally."
To most observers, City had appeared to be the better team on this day.
Though Nani had opened the scoring for United in the 41st minute, City equalized in the 65th when a shot from newly signed Edin Dzeko deflected off of Spanish mastermind David Silva.
But despite all of the questions, all of the criticism, all of the concerns about whether or not the England national had hit his peak as a striker can be put to rest for at least one day.
Wayne Rooney quieted them all with perhaps the most magical goal of his young, shining career.
Manchester United manager Sir Alex Ferguson called Rooney's winner perhaps the best goal he had seen in his 25 years at Old Trafford.
"It was stunning," he said. "[Nani's tally] was an unbelievable goal, but nobody in their right sense will even talk about it. All the talk will be about that winning goal—unbelievable.
"We've had some fantastic goals here but in terms of execution, you'll never see that."