Match ends, Preston North End 0, Derby County 1.
Tom Lawrence's free-kick was enough for victory at Preston as fifth-placed Derby ended an eight-game winless run.
Alan Browne's first-half penalty failure proved costly for North End, who missed the chance to leapfrog Derby into the Championship play-off places.
Browne hit the post from the spot after he had been fouled by Andre Wisdom.
A Derby side showing five changes from Friday's abject 4-1 home defeat by Sunderland did not have a shot at goal until Lawrence's 52nd-minute winner.
The Rams had slipped from second in the division in the two months since their previous victory and faced the prospect of dropping out of the top six had they not gained a positive result at Deepdale.
Preston enjoyed the better of the first half but Callum Robinson was the only player to test Scott Carson, the Derby goalkeeper saving his angled shot, while the former Aston Villa forward also headed and shot off target with further chances.
After Lawrence's goal, North End duo Paul Huntington and Paul Gallagher fired over with snapshots in the box, but they were unable to find an equaliser.
Derby managed only two attempts at goal in the match, but should have extended their lead through substitute Kasey Palmer, who fired wide from 12 yards.
Preston boss Alex Neil:
"Alan Browne is devastated because he thinks he's let people down but the fact is without him, we would not be in the position we are in - I told him that.
"The players are gutted after the game. I have no complaints with my players.
"The one thing we are all disappointed by is that we didn't show that little bit of quality at times. I couldn't have asked for much more, though, from my team."
Derby boss Gary Rowett:
"I couldn't give a monkey's if it didn't look attractive. We tried to look attractive (against Sunderland) and ended up losing to the bottom team in the league.
"Hopefully this will give the players that little bit of breathing space to go and play with a bit more confidence.
"I just think psychologically today it was a huge result. For us, it didn't matter how we got it or how ugly the performance was."
- 14FisherBooked at 88mins
- 4PearsonBooked at 43mins
- 29BarkhuizenSubstituted forBodinat 73'minutes
- 8BrowneSubstituted forMoultat 63'minutes
- 37RobinsonSubstituted forJohnsonat 79'minutes
- 23VydraSubstituted forPalmerat 74'minutes
- 10LawrenceSubstituted forHansonat 89'minutes
- 28NugentBooked at 68minsSubstituted forJeromeat 90+4'minutes
- Tony Harrington
- Shots on Target
Second Half ends, Preston North End 0, Derby County 1.
Offside, Derby County. Scott Carson tries a through ball, but Cameron Jerome is caught offside.
Attempt saved. Sean Maguire (Preston North End) header from the centre of the box is saved in the top centre of the goal. Assisted by Paul Gallagher with a cross.
Substitution, Derby County. Cameron Jerome replaces David Nugent.
Darnell Fisher (Preston North End) wins a free kick on the right wing.
Foul by Andreas Weimann (Derby County).
Offside, Preston North End. Louis Moult tries a through ball, but Sean Maguire is caught offside.
Foul by Sean Maguire (Preston North End).
Alex Pearce (Derby County) wins a free kick in the defensive half.
Substitution, Derby County. Jamie Hanson replaces Tom Lawrence.
Darnell Fisher (Preston North End) is shown the yellow card for a bad foul.
Foul by Darnell Fisher (Preston North End).
Tom Lawrence (Derby County) wins a free kick on the left wing.
Attempt saved. Billy Bodin (Preston North End) left footed shot from outside the box is saved in the centre of the goal. Assisted by Louis Moult.
Attempt missed. Paul Gallagher (Preston North End) left footed shot from the right side of the box is too high following a set piece situation.
Billy Bodin (Preston North End) wins a free kick on the left wing.
Foul by Andre Wisdom (Derby County).
Corner, Derby County. Conceded by Ben Pearson.
Foul by Paul Gallagher (Preston North End).