Louie Sibley celebrated his full league debut with a memorable goal as a Derby side missing Wayne Rooney beat Blackburn 3-0 to dent Rovers' Championship play-off hopes.
Rooney's absence was not felt as 18-year-old Sibley scored a first-half rocket before a Chris Martin double sealed an impressive afternoon's work for County.
Blackburn created little after Ben Brereton wasted an early opportunity and had John Buckley red carded in stoppage time as they missed the chance to climb into the top six.
How Rams eased to victory
All the focus before the game was on Rooney, who was not in the squad although the former England captain was at the ground. Graeme Shinnie replaced him in midfield and Blackburn started strongly, forcing a corner in the second minute which Tosin Adarabioyo headed over.
When the visitors won another in the ninth minute, the ball dropped for Brereton but he fired over from eight yards.
Derby fashioned a good opening in the 19th minute with Shinnie setting up Martin whose shot from just inside the area was pushed over.
There were strong Derby claims for a penalty in the 23rd minute when Martyn Waghorn went over but the home side took the lead four minutes later as Sibley fired an unstoppable 25-yard shot into the top right corner.
Blackburn looked rattled and Derby had a great chance to score again in the 37th minute when Craig Forsyth played Waghorn in but he failed to lift the ball over Christian Walton.
It was only a temporary reprieve because the second arrived four minutes later as Shinnie's drive was pushed out by Walton and Martin slid in the rebound.
It was almost game, set and match in the 44th minute. Waghorn went round Walton but his shot came back off the inside of a post and into the arms of the goalkeeper.
Blackburn needed a big improvement in the second half to get back in the game but Walton had to make a smart save to turn behind a Waghorn free-kick.
Rovers won a free-kick on the edge of the area in the 58th minute but Adam Armstrong drove it into the wall and Ben Hamer made his first save of note three minutes later when he turned behind a deflected shot from Amari Bell.
Derby's defence was starting to come under pressure yet Blackburn could not find the quality or invention to get back into the match.
And their fading hopes were ended in the 85th minute when Martin converted a penalty after Jason Knight was bundled over by skipper Elliott Bennett before Buckley was sent off for a late lunge on Curtis Davies.
What the managers said...
Derby's Phillip Cocu: "[Rooney] has a small muscle problem which will be assessed tomorrow to find out exactly what it is but we don't expect it to be a big issue and maybe he is available for the next game. He couldn't train on Saturday, he tried but it was not good enough and we didn't want to take the risk of him pulling a muscle and is out for the season. Tomorrow he will have a scan and then we will know a little bit more.
"Wayne was part of the team before in the preparation for the match, and at half-time and after the game he joined in with everybody. He observed from on high so he could see some tactical details so he was involved with the team."
Blackburn's Tony Mowbray: "We missed some good opportunities, goals change games and we didn't take the chances when they came and paid. We are disappointed, we came here with an ambition to get in the top six and believed that we could but Derby played well.
"We've got nine games to go, we've got a lot of teams to play that are around us so let's see where we go. We believe we can beat anybody at home and in spells today we showed we can be a threat away as well."