With a number of Development Squad players potentially in action for the first team on Wednesday, Danny Simpson was afforded some valuable game time, while also offering his experience to the Under-23s group during the Premier League 2 Division 1 clash in Seagrave.
The Foxes started in a 4-3-2-1 formation, with Dempsey Arlott-John and Kasey McAteer supporting lone forward Jake Wakeling. The early possession and chances belonged to the visitors, however, as Louie Sibley's speculative long-range effort flew well over the bar once he moved the ball through the centre of midfield.
And it was Sibley who created the opener after just seven minutes, breaking forward again and threading the ball through for left-wing back Dylan Williams, who slotted it past Jakub Stolarczyk.
The Rams quickly doubled their advantage with Liam Thompson's free-kick headed straight in by the unchallenged Cameron Cresswell, who nodded home the second after just 14 minutes.
City' youngsters looked for a route back into the game immediately via Callum Hulme's free-kick, which came out for Wakeling, whose cross-turned-shot from a tight angle was claimed at the near post by Derby 'keeper Manny Idem.
The hosts kept up a mini spell of pressure when Joe Bateman took too much time on the ball and almost allowed Oliver Ewing to nip in and grab a goal back, conceding a corner in the process, which Wakeling headed over.
Derby were very much still an attacking threat, however, and when the ball came out to Cresswell, he curled it wide of target. Another Hulme corner soon caused confusion in the Derby penalty area and after Idem twice failed to grab the ball, Johnly Yfeko tried to conjure an opportunity, but there was no way through.
Louie Watson then won back possession and fed his namesake Sibley, who struck well wide of the far post, trying to find the bottom corner. Back at the opposite end, Arlott-John's cross had to be punched away by Idem in the closing stages of the first period, as the Foxes applied some late pressure.
A series of Hulme corners followed, with Mitch Clark heading back across goal and Yfeko's volley, which looked to be heading on target, had to be blocked by Sibley. After making a change and moving to a three-at-the-back system at half-time, the Foxes were on top in the opening exchanges of the second period.
The lively Arlott-John, now operating in a more central position, shifted the ball onto his right foot but struck into the arms of the Derby stopper, before the breakthrough came. Wales youngster Will Russ, on as a half-time substitute, climbed highest to nod in Yfeko's cross from a lofted Hulme free-kick and get City right back into the contest.
Derby looked to respond through Sibley, whose left-footed free-kick sailed well over the bar before Stolarczyk had to be on hand to save his effort in the penalty box after Kornell McDonald picked out Sibley in the box.
Soon after, Russ' header was too weak to trouble Idem as he met Joe Wormleighton's centre and the forward was a target once more from Azeem Abdulai's looping cross, but this time the Derby stopper was able to claim the ball.
In a fast-paced encounter, Sibley shaped the ball onto his left and fired in a dangerous left-footed effort that whistled wide of the post, while another City chance came from Johnson Gyamfi, who managed to get a low shot away but again found Idem in the way.
And as Leicester poured more bodies forward, space opened up for Jayden Mitchell-Lawson, with Stolarczyk's reaction save tipping the Derby winger's strike onto the bar.
In the closing stages, Abdulai crossed for Russ, who tried to flick the ball with his back to goal, but he couldn't get the necessary power to beat Idem, before Arlott-John broke forward, finding Wakeling, who forced Idem into a smart diving save. But it wasn't to be for the Foxes, as the visitors held on for all three points.
Major moment…
With the home side trailing at the break, substitute Will Russ' goal gave hope of a comeback and sparked consistent pressure on the Derby goal, but they were unable to find another way through.
Who impressed?
Speaking during LCFC TV's broadcast, Matt Elliott said: "One player in particular stood out, Sammy Braybrooke. I like the look of him, he's a good little footballer. You think he's not going to be a defensive minded player, but he's worked hard, he's shown some good ability and he's tracked back well defensively."
Where does it leave us?
City's Development Squad remain 11th in the Premier League 2 Division 1 standings with 15 points from 15 fixtures.
Coming up…
The young Foxes will welcome Manchester City Under-23s to LCFC Training Ground next Monday (15 February) for matchday 16 in Premier League 2 Division 1 (7pm GMT kick-off).
The details…
City: Stolarczyk (c); Simpson (Wormleighton 70'), Abdulai, Clark, Ykefo; Hulme (Gyamfi 57'); Ewing (Russ 46'), Braybrooke; Arlott-John, McAteer; Wakeling.
Subs not used: Doherty, Kutshienza.
Goal: Russ 54'.