A first-half goal from Lewin Nyatanga on his first appearance for Derby since September was enough to condemn Luton to League One at Pride Park on Friday night.
But the visitors put up a spirited fight and, although Derby had the better chances, the result was in doubt right up until the end.
"The players put on a a terrific performance. I'm so proud of them and this has definitely given me something to work with," said Blackwell, who only took charge at Kenilworth Road in March following the sacking of Mike Newell.
"We dominated large parts of the game, but we lacked a that bit of knowledge.
"We've a dynamic new chairman, and with some of the young players we have the club has a future."