With Rovers boss Paul Trollope freely admitting that it was a 'smash and grab' result, they scored completely against the run of play when Rochdale old boy Rickie Lambert converted the simplest of close-range chances on 54 minutes.
Right from the off the home side, much improved over the last four games, tore into the play off chasing visitors but saw striker Glenn Murray miss three headed chances as wing play by Adam Rundle and Kelvin Etuhu stretched the Rovers defence.
Murray was also unlucky to see a fiercely struck effort hit the woodwork with Phillips beaten, as was Rundle when his drive from the edge of the penalty area crashed against the bar.
With Phillips producing saves to deny skipper Gary Jones and the livewire Chris Dagnall it was becoming a frustrating afternoon for the home side and its fans.
Though Rochdale started the second half the brighter, Rovers took an undeserved lead when Lambert tapped home from close range after good work by Craig Disley.
Undaunted by falling behind, Rochdale continued to make chance after chance but could not find a way through an overworked Bristol Rovers rearguard.
Phillips produced a stunning save to keep out a Murray header, and in time added on went even better with two acrobatic efforts to keep out substitute Joe Thompson and fullback Alan Goodall.
The result leaves Rochdale in trouble, moving towards the bottom part of the table, but moves Rovers into the play off positions.