A week on from the goalless draw at Reading, the young Foxes were back on the road at Proctor Cars Stadium, and made the short trip back across the Midlands with all three points secured.
The first big moment in the contest occurred just two minutes in when Rams goalkeeper Harley Price was shown a straight red card, leading to an early change for the 10-man hosts.
It took until the hour-mark for City to make the breakthrough, with captain Sammy Braybrooke converting a spot-kick to finally break through.
Leicester grabbed a second with 73 minutes on the clock; Brandon Cover setting up substitute Ryan Donnelly, who made an instant impact after coming off the bench.
That sealed a second win in three PL2 games, and we now sit second in the table, on seven points from nine games, ahead of heading back to LCFC Training Ground for a meeting with Tottenham Hotspur on Friday 19 September.
Before then, attention turns to the Premier League International Cup, taking on Juventus in our first group game at Seagrave on Wednesday 10 September, following the international break (both 7pm BST kick-offs).
The details...
City: French, Cover, Khela, Gray, Ali; Neale (Onanaye 77'), Braybrooke; Fisken (Otchere 56'), Golding (Donnelly 67'), Briggs; Richards (Omobolaji 77').
Unused sub: Donohue.
Goals: Braybrooke (p) 60', Donnelly 73'.