Kevan Hurst and Caleb Folan put the home side in control before half-time and although Blackpool never gave in, they could not avoid a first defeat in eight games.
The biggest threat to Chesterfield was the driving rain which left pools of water on the pitch and made passing a lottery at times, but the weather improved and referee Ray Olivier was never likely to have abandoned the contest.
Blackpool did not play with the same conviction that had brought them so much recent success but the loss of striker Keigan Parker with a stomach bug was a big blow.
The visitors lacked pace up front and, although they had plenty of possession in the first half, it was Chesterfield who had the cutting edge.
Both goals were quality and Hurst signed off in style before returning to Sheffield United at the end of a six-month loan spell.
The winger finished confidently after Folan broke down the Blackpool right and set him up to guide a right-foot shot inside Rhys Evans' left-hand post.
Hurst could have added a second after beating two defenders but this time his shot was too high and Scott Vernon was also wide of the mark when he lifted a shot over the bar after Claus Jorgensen set him up.
That miss was to prove costly when Folan broke away again in the 42nd minute and, after leaving Shaun Barker and Michael Jackson trailing, he sidestepped Evans to score from eight yards.
The conditions became extremely difficult at the start of the second half but once the rain eased the pitch remained playable, although Blackpool did not look like forcing their way back into the match.
Former Chesterfield defender Ian Evatt was pushed forward to add height and strength to the attack and he forced Barry Roche into a diving save with a shot from 20 yards.
Evatt also laid on a chance which both Keith Southern and Vernon failed to convert, but his afternoon ended with a booking which means he now serves a one-match ban.