Blues dominated the first-half at Wast Hills and could easily have been 3-0 up at the break had they had they taken their chances.
But they petered off in the second-half and allowed the young Rams back into the game. Jamie Hanson scored the only goal from a terrific free-kick on the hour-mark.
"I was very pleased with the first half performance and arguably we could have been at least three goals up," said Spooner. "But we weren’t clinical or determined enough to kill the game off while we had the opportunity.
"I felt we contributed to the goal in the build up to the free kick. There was a sloppy pass and one of our players didn't get close enough. But it was a fantastic goal and their lad has put it straight in the top corner."
Spooner (pictured above) continued: "At 1-0 down we seemed to accept mentally that they weren’t going to get something, whereas in the past we’ve rolled their sleeves up and created numerous chances. As good as we were in the first half; we were poor in the second half.
"But credit should also go to Derby they because stopped us being able to move the ball as quickly and our movement wasn’t as good up the top. Everything became straight and we didn’t get in behind and consequently the play was all within five or ten yards in their half or in the midfield and we couldn’t find a way through.
"On top of that their goalkeeper has made some fantastic saves and I just felt we should have been more ruthless in the first half."