© PA Photos
The visitors had the first sight of goal of the match when Andy King met a cross in the box, but he could only steer his header over the bar from 12 yards out.
Lloyd Dyer almost pulled his side back level when Jeffrey Hendrick lost the ball in midfield for Derby. Leicester came forward with it, eventually finding Dyer inside the box, but he swept his first-time effort wide.
Ward and Keogh almost combined for another goal midway through the half, but this time the latter couldn't beat Kaspar Schmeichel with his header.
The Foxes almost made it two goals in as many minutes immediately afterwards, but Frank Fielding was equal to Nugent's effort from just inside the box.
Ben Davies was the next to come close, almost restoring Derby's two-goal advantage with a fine strike from 25 yards that went just over.
Fielding kept his side in the lead with 20 minutes left on the clock by saving a Ben Marshall strike that looked destined for the net.
The hosts held out in the closing stages to secure their first win in their last nine matches.