Boro fell two goals behind in the first half at Pride Park after goals from strikers Lee Gregory and Colin Kazim-Richards.
The visitors did manage to pull a goal back before the break through Neeskens Kebano but weren’t able to build momentum after the interval.
Neil Warnock’s side have now gone five games without a win and slipped six points adrift of the Championship play-off places.
Boro will now hope to get back to winning ways when they host Huddersfield on Tuesday – but will have to manage without new signing Yannick Bolasie.
The winger missed the Derby match with a hamstring issue and is set to be sidelined for a while.
Our Boro writer Joe Nicholson has dished out his marks from the fixture – scroll down and flick through our gallery to see them:

1. Marcus Bettinelli - 5
Couldn’t do much about either goal and didn’t have many saves to make in the second half when Derby dropped off. 5 Photo: Alex Pantling

2. Darnell Fisher - 5
Was caught out of position a couple of times and had to make a couple of fouls to prevent Derby attacks. 5 Photo: Getty Images

3. Paddy McNair - 5
Endured a tough first half against Derby’s front two. Moved into midfield after half-time and saw more of the ball. 5 Photo: Alex Pantling

4. Anfernee Dijksteel - 4
Unconvincing at centre-back as Derby launched balls forward to their front two in the first half. 4 Photo: George Wood


