Match ends, Blackburn Rovers 1, Derby County 0.
Adam Armstrong scored the only goal of the game as Blackburn Rovers made it four straight wins with victory against a lifeless Derby County side.
Armstrong, who was denied by Rams goalkeeper Ben Hamer just before the break, finally put the hosts ahead with a fine shot from the edge of the area.
The former Newcastle forward almost added a late second, only to see his shot deflected over, and while the Rams then pressed for an equaliser, Rovers held on.
Wayne Rooney, England's all-time top scorer, was again on the Derby bench as coach but could only watch on as the Rams struggled in attack, with their only shot on goal coming in the 94th minute.
Christian Walton's injury-time save from Jack Marriott ensured maximum points for Tony Mowbray's Rovers, making it 14 from a possible 18 in a six-match unbeaten run at home dating back to 1 October.
The defeat was Derby's fifth in a row away from home and leaves Phillip Cocu's side winless on their Championship travels since the opening weekend of the season.
Blackburn looked the more menacing throughout, with Bradley Dack twice off target before Armstrong tested Hamer with the only shot on target from either side before the break in the 45th minute.
Hamer, however, was then beaten at his near post as Armstrong lashed home after meeting a fine pass from Corry Evans.
Krystian Bielik sent a curling shot just wide for the Rams and Rovers' Ryan Nyambe crucially blocked a Kieran Dowell effort either side of Armstrong's decisive strike, but it was not until Marriott's injury-time shot that Walton was tested in the home goal.
Blackburn manager Tony Mowbray:
"It felt as if we should have made it more comfortable. I've just been speaking to Adam; if he'd have taken his chance first half, with the rocket he scored in the second half, it would have put a better balance on the game for us.
"At 1-0 it's always dangerous but I think our collective spirit has got us through.
"The team controlled vast swathes of that game really. Good composure, created chances - not enough chances for the possession we had but still we'll take the points.
"It was important for us to win because I think when you've won three in a week, it's easy to think you're a decent team and drop off the intensity, and we worked hard to make sure the intensity was there and they produced a good performance on the back of that."
Derby boss Phillip Cocu:
"We struggle creating, taking shots on target. If we get shots, especially in away games, they're not on target.
"We had a slightly different approach. We wanted to stay in the game for as long as possible, so it was more compact, especially against a team that really likes playing transitions.
"When they win the ball, they score a lot of goals through speedy wingers and (Bradley) Dack is a very clever player.
"That part of the game, the lads did good. But when we had the ball, in the first half, it was unnecessarily sloppy. We didn't create a lot. Second half, we tried to push more forward and I think we did well."
- 29EvansBooked at 62mins
- 7ArmstrongSubstituted forBuckleyat 90+1'minutes
- 8RothwellSubstituted forBennettat 83'minutes
- 10GrahamSubstituted forGallagherat 68'minutes
- 5BielikSubstituted forMartinat 66'minutes
- 37BogleSubstituted forWhittakerat 80'minutes
- 9WaghornSubstituted forMarriottat 81'minutes
- 10LawrenceBooked at 18mins
- Oliver Langford
- Shots on Target
Second Half ends, Blackburn Rovers 1, Derby County 0.
Corry Evans (Blackburn Rovers) wins a free kick in the defensive half.
Foul by Curtis Davies (Derby County).
Attempt saved. Jack Marriott (Derby County) right footed shot from the centre of the box is saved in the bottom right corner. Assisted by Chris Martin.
Foul by Sam Gallagher (Blackburn Rovers).
Curtis Davies (Derby County) wins a free kick in the defensive half.
Attempt missed. Jack Marriott (Derby County) header from the centre of the box is close, but misses to the right. Assisted by Duane Holmes with a cross.
Substitution, Blackburn Rovers. John Buckley replaces Adam Armstrong.
Elliott Bennett (Blackburn Rovers) wins a free kick in the defensive half.
Foul by Curtis Davies (Derby County).
Corner, Derby County. Conceded by Tosin Adarabioyo.
Attempt blocked. Morgan Whittaker (Derby County) left footed shot from outside the box is blocked.
Foul by Corry Evans (Blackburn Rovers).
Morgan Whittaker (Derby County) wins a free kick in the defensive half.
Corner, Blackburn Rovers. Conceded by Andre Wisdom.
Attempt blocked. Adam Armstrong (Blackburn Rovers) right footed shot from the centre of the box is blocked. Assisted by Bradley Dack.
Attempt saved. Bradley Dack (Blackburn Rovers) left footed shot from the right side of the box is saved in the bottom right corner. Assisted by Elliott Bennett.
Corner, Blackburn Rovers. Conceded by Tom Lawrence.
Attempt blocked. Corry Evans (Blackburn Rovers) left footed shot from the centre of the box is blocked.