Well-taken goals from Danny Boshell and Adam Griffin in the space of six first-half minutes, followed by a late Keith Briggs goal provided some welcome relief from the spectre of relegation, while underlining County's resurgence under Jim Gannon.
This was Stockport's biggest win of the season, and it means they have lost just one of their last nine league games.
Matt Hamshaw, a 13th-minute substitute for head injury victim Liam Dickinson, provided a rare moment of finesse in an otherwise disappointing opening 20 minutes when he controlled a long clearance with his first touch and, with his second, fired narrowly over the crossbar from 25 yards.
Ernie Cooksey wasted Rochdale's best chance of the first half, dragging a left-footed volley wide following David Beharall's weak headed clearance.
Within seconds Stockport were ahead, Griffin creating space on the left and feeding Hamshaw, who laid the ball off for Boshell to deliver a curling shot into the left corner of Matthew Gilks' goal.
County's second goal was fashioned down the opposite flank, Briggs making his way to the byline before crossing low for Griffin to steer the ball adroitly past Gilks in the 33rd minute.
Stockport goalkeeper James Spencer was called upon to make a fine, flying save to keep out Chris Dagnall's shot, albeit from a prohibitive angle, while Tes Bramble and Briggs saw efforts go narrowly wide at the other end of the pitch.
Rochdale, emboldened no doubt by manager Steve Parkin's half-time teamtalk, were markedly more committed after the break.
Rickie Lambert, booed throughout by the Stockport fans who once adored him, sent several long-range strikes wide of or over Spencer's goal, and Gary Jones also failed to find the target with a low, left-footed drive from the edge of the penalty area.
Gilks' awareness denied Bramble a goal in the 69th minute, snuffing out the danger at his near post following good work from Boshell and Griffin.
Briggs atoned for a wasted free header when he raced on to substitute Adam Le Fondre's throughball and rounded Gilks three minutes from time.