Caleb Folan made the most of his brief appearance when he grabbed a dramatic late winner to punish a mistake by on-loan goalkeeper Brad Jones.
Middlesbrough's Australian international has always looked suspect on crosses and in the third minute of stoppage time he missed a long throw and Folan made him pay.
The result was a deserved one for Chesterfield who dominated the game and always looked likely to break through with the pace of French striker Tcham N'Toya-Zoa. Wayne Allison was also a threat to Blackpool who created little apart from an early chance which the young striker Matthew Blinkhorn wasted.
Blackpool had to defend in depth at times but they would have been trailing before half time if Allison had not spurned a good chance in the 42nd minute.
The experienced front man drove a shot against the bar from inside the six yard box after a corner had been headed on.
The rest of the game followed a similar pattern with Chesterfield making the running and Blackpool desperately hanging on.
Mark McGregor cleared an Allison shot off the line after Jones had made a mistake and N'Toya-Zoa was close to turning in a low cross from Campbell-Ryce.
But Blackpool somehow survived and came close to snatching the lead when substitute Jamie Burns headed straight at Carl Muggleton.
The introduction of Folan almost brought a goal when the striker cut inside and shot just wide from the edge of the area and another mistake by Jones almost gave him an 84th minute goal.
The keeper came out unconvincingly and Folan saw his goal-bound shot fly just wide off the keeper's shoulder.
Danny Coid had a low shot beaten out by Muggleton in the 90th minute, the game appeared to be drifting to a draw until Jones blundered again but this time it proved costly.