Substitute Adam Le Fondre's late goal settled a pulsating game which moved Rochdale into the top seven and at the same time ended Bradford's slim hopes of joining the play-off race.
Rochdale got off to the best possible start by scoring after just 27 seconds as David Perkins took full advantage of some poor defending to fire home from the edge of the box.
Like a tennis match, the game swung from end to end and the visitors were level on the hour mark when, following a foul by Tom Kennedy on Joe Colbeck, a penalty was awarded and Peter Thorne calmly converted.
Rochdale then calmly took control and, with just two minutes remaining, Le Fondre latched on to a Lee Thorpe flick to fire home his 14th goal of the season.
The dying seconds saw City camped in the home side's penalty area and Barry Conlon missed a great opportunity to secure a share of the spoils by heading against the crossbar from close range.