McClaren was especially delighted with the effort and energy shown by his players after coming back from an early Blackpool goal.
A hat-trick from Chris Martin and goals from Craig Bryson and Richard Keogh cancelled out Isaiah Osbourne's opener for the Seasiders as Derby overcame the first-half deficit in style.
"We said at half time its a case of staying in the game and we'll get stronger because we have a fit bunch here," McClaren said.
"That's basically what we did, we ground Blackpool down, made them make errors and lose concentration and we scored some great goals.
"We felt our tempo wasn't right in the first half it was a case of when we lost the ball we allowed Blackpool too much time on the ball and too much possession and that's not our game, at half time we brought on Johnny Russell, we played higher up the park and make sure when we lose it we win the ball back."
McClaren added: "We got a bit of luck with the goal coming 40 seconds into the second half with that penalty but over 90 minutes we wore the opposition down to get the result."
On the subject of hat-trick hero Martin, McClaren was quick to point out the striker's significance in the side.
"Everybody's contributed and we're getting 10, 20, 30 per cent more from the players each week and Chris is out focal point, he's the one everyone can play off.
"We don't want to stop the run, our first job was to try and bring the crowds back and play the kind of football that would encourage that, the players have done that and I've inherited a good squad."