An impressive all-round performance by Chesterfield was too much for an out of sorts Rochdale who were punished by the clinical finishing of Jack Lester.
The striker scored twice to take his tally for the season to 19 and Gregor Robertson added a third near the end to put the seal on an excellent night for the home side.
Rochdale were second best and Chesterfield could have been ahead as early as the fourth minute when the visitors survived a double scare.
First Frank Fielding had to dive to his left to keep out a fierce drive from Lewis Montrose and when Lester picked up the rebound, his left foot shot curled just wide.
Another good move from Chesterfield almost ended with Derek Niven connecting with a cross and Jamie Lowry was almost in when the visitors were caught on the break.
But it was defensive hesitation which opened the door for the home side in the 34th minute when Rochdale's centre halves failed to clear a bouncing ball and Lester nipped in to beat Fielding from 12 yards.
Rochdale posed little threat before the interval but they were more menacing in the second half when Chris Dagnall started to cause problems on the right.
But it was Chesterfield who struck again in the 61st minute when Lester turned away from Scott Wiseman on the edge of the box and drove a low shot past Fielding's outstretched left hand from just inside the area.
Rochdale pressed forward but created few openings and it was Chesterfield who had the better chances on the break.
Lester was denied a hat-trick by a fine save from Fielding in the 85th minute but 60 seconds later, the game was over when Chesterfield scored again.
It was a well worked goal that saw Llloyd Kerry and Martin Gritton combine before Kerry back-heeled the ball through for Robertson to burst into the area and finish from 15 yards.
The victory keeps Chesterfield on course for the play-offs and was a reminder to Rochdale that they have a lot to do to secure automatic promotion.
