Wigan memorably overcame their illustrious opponents in the final last year as Ben Watson struck the only goal at Wembley.
And despite being without Watson, who broke his leg last month, Wigan produced a repeat effort this time winning 2-1 at the Etihad Stadium on Sunday.
Jordi Gomez's penalty and James Perch's strike rendered Samir Nasri's volley a mere consolation and booked Wigan an FA Cup semi-final clash with Arsenal.
When asked whether the win represented his greatest moment in football, Rosler - a former City striker who enjoys cult status among the fans - told BT Sport: "In management, yes probably.
"Everybody knows my ties to Manchester City but I made it clear I am very happy and excited to be the manager of Wigan. I kept my emotions in control and I was just focussing on the job at hand."
Wigan chairman Dave Whelan paid tribute to Rosler, who has reversed Wigan's fortunes in the Championship since replacing Owen Coyle.
"Nothing can compare with actually winning the cup but to come here and win, and go back to play Arsenal in the semi-final, is a dream," he said.
"The last five minutes seemed like 50 minutes. It's all down to this lad, Uwe. He has got these lads believing."