Martyn Waghorn's first-half goal was his first in eight matches
Substitute Martyn Waghorn grabbed the only goal as Derby County beat high-flying Preston North End to earn a fifth successive home win.
Waghorn, one of two enforced first-half replacements for the Rams, chested the ball in from almost on the line after Curtis Davies had flicked on a Duane Holmes corner.
Derby created the better opportunities throughout and should have had more to show for it than the striker's fifth goal of the season.
Holmes hit the bar with a first-half volley at 0-0, Waghorn went close on three occasions and the excellent Tom Lawrence was narrowly off target with a couple of fierce strikes.
Preston, who dropped a place to third in the Championship table following Leeds United's win over Luton, were below par in the first period but improved after the interval.
The closest they came to salvaging a point was when Tom Barkhuizen's tap-in following a corner was ruled out for offside.
The Rams, who climbed to 11th, should have been further ahead by the time Preston began to find the form that has seen them among the division's frontrunners.
Lawrence was the main attacking influence in a dominant opening period for the hosts, shooting wide early on and then linking up nicely with Chris Martin to tee up the Holmes chance that crashed against the bar.
Waghorn, one of two substitutes following injuries to Mason Bennett and Graeme Shinnie, should have opened the scoring with a glorious one-on-one chance, but saw his left-foot shot deflected over by Rudd.
But he made amends with his fifth goal of the season from close range soon after.
The second half proved more open, with Waghorn twice wasting chances to double the lead, and Lawrence, who remained the best attacking player on display, narrowly off target with a fierce strike.
Preston caused some nervy moments in the closing stages but could not find a leveller.
Derby manager Phillip Cocu:
"I think it was one of the best 45 minutes I have seen from the team. It was a great combination of tactical execution of the game plan and doing what we wanted to do.
"It's what you want to see and we could have made it a bit easier for ourselves and scored an extra goal, but the team recognises this more and more.
"You don't force it and go forward with everybody but just try to keep your organisation and if you don't score a second one you make sure you have a clean sheet, so this is a positive development because it would have been a shame if we had drawn after playing 60 minutes of great football."
Preston boss Alex Neil:
"I thought first half we lost too many headers, too many battles all over the pitch and Derby were faster, sharper and better than us.
"Like I said to them at half-time, it's quite easy for me to come in and start shouting and bawling and tell everybody how poor they've been but nothing is won at the moment and we are going to lose games along the way.
"The players understand and are frustrated for themselves, but at the end of the day, we win and lose as a team. Sometimes I'll get it wrong, sometimes they won't perform and that's part and parcel of it."
