In a scrappy game of few chances it was perhaps fitting that the winning strike came courtesy of an own goal when visiting skipper Danny Foster deflected an Adam Rundle cross into his own goal.
New boys Dagenham & Redbridge had clearly done their homework and set out to frustrate the hosts who, though difficult to beat this season, have struggled to win at home.
The only chance of note in a dire first half saw referee Foster rule out what appeared to be a perfectly good Dagenham goal when David Rainford toe-poked home from close range after the home defence had failed to clear a corner.
The introduction after the break of Adam Le Fondre and Kallum Higginbotham did enliven the home side with Higginbotham in particular showing some tricky and direct play.
The game's deciding goal came on 59 minutes when Rundle delivered a right-footed cross from wide on the left and, with no forward challenging him, Daggers skipper Foster managed to deflect the ball beyond the outstretched fingers of keeper Tony Roberts.
Having fallen behind, Dagenham made three changes in an attempt to get back into the game and created a couple of half-chances that Paul Benson and Ben Strevens failed to convert.
In stoppage time Rochdale's leading scorer Glenn Murray saw his effort go wide and midfielder David Perkins forced Roberts to make a smart save from his drive on the edge of the penalty area.
With a game in hand, Dale have moved to within reach of the play-off positions while Dagenham, who had a bad day all round having been stuck in motorway traffic on the way to the game, have slipped uncomfortably close to the relegation places.