Wayne Rooney secured his first win as permanent Derby manager with a 1-0 victory over stumbling promotion chasers Bournemouth.
Krystian Bielik's first-half strike proved the difference as the Rams moved out of the relegation places.
The Cherries lost further ground on the top two, dropping to fourth after Reading's win over Coventry, having won just one of their last six league games.
Even the late introduction of Jack Wilshere, who agreed terms with the club until the end of the season on Monday, failed to inspire Jason Tindall's side as they fell to a second successive defeat.
Derby started with plenty of intent and Kamil Jozwiak almost gave the hosts an early lead.
The Pole beat his marker at the back-post but saw his goalbound header turned behind by alert Bournemouth goalkeeper Asmir Begovic.
The visitors then wasted a glorious chance when a simple diagonal punt found Jack Stacey on the right flank and his whipped cross just evaded the lurking Dominic Solanke.
A lengthy stoppage then followed after a head injury to Bielik.
Derby's troubles in front of goal have been evident this season and they were perfectly encapsulated on the half-hour mark.
Lee Buchanan suddenly found himself bearing down on goal inside the box but his effort was too tame and allowed Begovic to smother it to safety.
But the hosts' frustration was short-lived as just a minute later they were toasting an opener - and it was Bielik who got it.
The midfielder rose highest from a corner and saw his header partially blocked, before reacting quickest and stabbing home.
Bournemouth made two changes at the interval in a bid to get back into the game and one of them, Josh King, came close to an immediate leveller only to plant a header straight at home keeper Kelle Roos.
The game was starting to open up with Solanke firing a half-volley into the side netting before Nathan Byrne failed to get enough power behind his shot down the other end.
Derby could have doubled their lead just after the hour mark when Matt Clarke met a corner with a stooping header but the feet of Begovic kept the defender's effort out.
Bournemouth upped the ante heading into the final quarter of the game and Wilshere's arrival came with 13 minutes to go.
It was the former Arsenal and England man's first appearance of any kind since a League Cup tie for West Ham last September.
The visitors pushed and probed, with Solanke seeing a header well kept out by Roos, but a resolute Derby held out for a precious victory.
What the managers said...
Derby's Wayne Rooney: "To get any win is great. Obviously I've not been looking at it like that (first win) as I've been doing it a while but yeah I'm delighted. But most of all I'm really pleased for the players. It shows what a difference it makes playing with more desire, and that desire to stop crosses.
"I demanded a reaction tonight and in fairness it has been a difficult couple of weeks. I felt this game had a lot of pressure on us tonight. There's only one game lately where I've been disappointed in us and that was the loss to Rotherham last week. But I was delighted with their reaction tonight."
Bournemouth's Jason Tindall: "I felt we weren't at our best in the first half. We had a big moment early on with Dom Solanke's chance after two minutes. And then I was disappointed to concede from a set-play but they (Derby) were better in the first half, hence why I made changes at the break.
"We huffed and puffed second half but we couldn't break them down. We had a lot of the ball but just couldn't force it. We weren't good enough and didn't ask enough questions of them. We didn't take our chances when they came along. It's one of those things we're going through. We're struggling to score goals. I still believe that we'll score goals. We just need to ask more questions of the goalkeepers. It's been a disappointing week to say the least, with just one point from nine, but it's about how we bounce back now."