Substitute Lukas Nmecha was the hero, netting an impressive hat-trick to add to Benjamin Garre's open as City walked away from the Academy Stadium with three points.
The first half progressed slowly with Derby County securing the first chance of the game as Lewis Walker’s strike was shifted around the left post by goalkeeper Aro Muric.
Muric was called upon just moments later and this time the keeper comfortably caught Charles Vernam’s straight fired shot.
City pressed on, and Demeaco Duhaney’s clever footwork just outside the box nearly resulted in a goal for Tom Dele-Bashiru.
The EDS’ hard-work and determination was rewarded after 21 minutes as Brahim Diaz rippled around the defence to find Garre, who netted a low shot into the goal.
Rabbi Matondo looked threatening throughout the first-half, and nearly struck with a curled shot which look destined for the top left corner, but was well-saved by Derby stopper Josh Banks.
Their efforts meant the Blues went into the tunnel 1-0 up at half-time.
On their return to the pitch, Diaz was substituted for Nmecha, who made an incredible impact.
Within seconds of his introduction the striker won a penalty and promptly converted the spot kick himself.
Almost ten minutes later he did the same, calming slid his second goal into the net.
The hat-trick was completed with a fine close-range strike which flew straight passed Banks, and meant City confidently executed the final 20 minutes until added time when Derby County managed to claw a goal back.
How they lined up
Aro Muric stepped up to feature in goal against Derby County, while Demeaco Duhaney, Tosin Adarabioyo, Ed Francis and Tyreke Wilson made up City’s defence.
In midfield, skipper Jacob Davenport accompanied Rabbi Matondo and Tom Dele-Bashiru while Brahim Diaz and Benjamin Garre flanked Sadou Diallo.
What it means
City secured their second set of three points in the Premier League 2, which takes their current tally up to nine points in eight games.
Next, Simon Davies' side face Bradford City away at the Northern Commercial Stadium in the Checkatrade Trophy.
The match will take place on Tuesday 24 October, with kick-off at 6.30pm.