Owen spent eight years playing for United's bitter rivals Liverpool but Sir Alex Ferguson signed him this summer - and the 29-year-old scored his second goal for the club to seal a 4-3 win deep in stoppage-time against City.
When asked if that would confirm hero status with United fans, Owen told Sky Sports: "Yes, if there was any doubt before then maybe. It was always going to create noise when I joined but even if the fans didn't take to me you're never going to pass up an opportunity to play for team like this."
City equalised three times before Owen struck.
Wayne Rooney opened the scoring before Gareth Barry took advantage of Ben Foster's error. Darren Fletcher scored two headers, with Craig Bellamy levelling twice for the visitors.
"We dominated and the lads played well for a lot of the game," Owen added. "There were individual mistakes but over the years before I was here the defence has been fantastic."
Fletcher added: "It was an unbelievable match, we showed great character to come back. The goals were mistakes but we look at the positives - we showed character to the end."