Derby 0-3 Blackburn
Michael Appleton oversaw his first win as Blackburn manager as they eased into the fifth round of the FA Cup with victory at Derby.
Colin Kazim-Richards pounced on a defensive error to fire Rovers ahead shortly before the break.
The visitors had the better chances in the second half and Scott Dann volleyed in a second just after the hour.
Jordan Rhodes completed the scoring for Blackburn soon after, lifting the ball over the Derby keeper.
For the first 40 minutes or so the game was hardly an FA Cup classic, with both sides creating very little.
It took until the 26th minute for a chance on goal to materialise as Morten Gamst Pedersen's powerful free-kick was pushed away by Derby goalkeeper Adam Legzdins.
The opening goal arrived a minute before the break as Richard Keogh missed his clearance from a long ball by Jason Lowe and Kazim-Richards reacted quickly to race through and fire beyond Legzdins.
Derby managed their first chance on goal just before the half-time whistle as John Brayford volleyed weakly at Jake Kean.
The home side's struggles to work the Blackburn defence continued in the second half, but they should done better just before the hour when Jamie Ward found space, only to fire weakly at Kean.
Blackburn added a second in the 66th minute through Dann, who was picked out by Danny Murphy and the defender rifled a volley into the net.
Derby were just recovering from that strike when Blackburn scored a third to end the game as a contest. The excellent Marcus Olsson fed a pass to Rhodes, who lifted the ball over the Derby keeper for his 17th goal in a Blackburn shirt.
The hosts had a chance to snatch a consolation eight minutes from time but Jeff Hendrick headed wide.
Derby manager Nigel Clough:
"Blackburn were a bit too good for us although there was nothing in it until we paid for a bad mistake with their first goal just before the break.
"After that, their experience and physical strength shone through and our young lads found them hard to handle.
"Jordan Rhodes and Colin [Kazim] Richards are as big a handful as any attacking partnership at our level and it was also a tough task for our kids to come up against a player like Danny Murphy in midfield."
Blackburn manager Michael Appleton:
"I'm delighted to be making progress in the competition but I still believe we need to bring in a couple more players before next Thursday's [transfer] deadline if possible. There is still plenty to play for in the league and areas where I would like to see us being able to call on reinforcements.
"I don't have a budget as such but I am sure the owners would support me if I went to them with a viable deal for the right players.
"Victory is all-important in the cup but keeping a clean sheet at a place like Pride Park is also a big plus for us. I believe in trying to build a platform and a structure that makes it hard for the opposition to score or get behind us and there were very pleasing signs of that sort of shape developing."