Tom Ince's goal just before the break gives the Rams the points
The former Liverpool wideman found the net with a left foot strike five minutes before the break to give the Rams a second successive win at Portman Road.
Blues had chances, Freddie Sears and Daryl Murphy going close and Jonathan Douglas had a header cleared off the line but couldn’t find a way to breach Lee Grant’s goal.
Town remained unchanged for the fifth successive game, with Luke Varney on the bench for the first time as a Blue having signed a contract until the end of the season.
Sears tested Grant on five minutes with a low drive from the edge of the box, Brett Pitman sending in a terrific right foot cross that just evaded Murphy.
Bradley Johnson fired just wide for the visitors after Ince had created problems in the Town defence, then a terrific pass from Johnson found Ince on the break and it needed a great block from Tommy Smith to prevent Chris Martin’s shot testing Dean Gerken.
Gerken was tested by Ince moments later, diving to his right to keep out a 25 yard free-kick while at the other end a cushioned header from Murphy set Sears free but his cross was cleared from danger as Pitman challenged.
Sears had a shot blocked by Cyrus Christie, then Gerken got down to smother Jacob Butterfield’s long range strike, Sears firing wide with a half chance in an entertaining first half hour.
Ince - like Sears - was causing problems on the flank and he dragged his shot wide, then Christophe Berra was in the right place to quell the danger from Stephen Warnock’s cross after a rapid counter attack from the Rams.
It was from another break that Derby took the lead on 40 minutes, Martin fed Johnny Russell, the ball cannoned back off him into Ince’s path and his strike took a slight deflection off Jonas Knudsen to beat Gerken and give the visitors the lead at half-time.
Murphy headed over after more good work from Sears as the second-half got underway with Blues on the front foot, Knudsen firing well wide from the edge of the box.
Ryan Fraser replaced Pitman just before the hour, the Bournemouth loanee getting a warm ovation from the Blue Army on his first game back after injury.
Christie’s excellent cross evaded Martin at the far post, before Town made a second change with Kevin Bru on for Ainsley Maitland-Niles.
Fraser almost forced his way to goal to goal with his first touch, the Scotland U21 international’s pace injecting an added dimension to the Town attack.
Sears was crowded out inside the Derby box, Murphy denied from Luke Chambers’ cross as Blues pressed for an equaliser.
Andreas Weimann replaced Russell for the closing stages, Douglas seeing his header cleared off the line before Ince saw yellow for a high challenge on Fraser.
Varney was handed the last eight minutes, Douglas making way as Mick McCarthy made a final change but despite pressing the Rams back, Town couldn’t find that elusive goal and it took an excellent save from Gerken to stop Johnson making it two with virtually the last kick.
Town: Gerken, Chambers, Smith, Berra, Knudsen, Skuse, Douglas (Varney 83) Maitland-Niles (Bru 62), Sears, Pitman (Fraser 58), Murphy. Subs not used: Bialkowski, Malarczyk, Coke, Oar. Booked: Berra, Douglas.
Derby: Grant, Christie, Warnock, Keogh, Shackell, Thorne, Johnson, Butterfield (Hendrick 82), Ince (Baird 90), Russell (Weimann 78), Martin. Subs not used: Mitchell, Pearce, Shotton, Bent. Booked: Butterfield, Ince.