On St. Georges' Day, the Bees were slayed, with the Daggers scoring either side of the break.
The visitors rarely produced the classy football that has kept them at the top of the league since September, their minds perhaps on football in League Two next season.
Craig Mackail-Smith put the home side ahead from a Paul Bruce corner in stoppage-time at the end of the first half.
The Daggers doubled their lead six minutes after the re-start, Glen Southam pouncing after some good work from Scott Griffiths from the left.
On the few occasions Barnet threatened Tony Roberts' goal, they found a solid Daggers defence with Ashley Vickers and Anwar Uddin in particular having inspired games.
Bees midfielder Nicky Bailey should have found the target after 11 minutes, but failed to test Roberts when clean through.
Keeper Shane Gore, playing his last game for Barnet, saved well from Chris Moore, before denying Jake Leberl's header four minutes before half-time.
Dagenham however took the lead in injury-time when Bruce's corner deceived everyone except Mackail-Smith who tapped into an empty net.
The Bees failed to respond and found themselves further behind on 51minutes. Scott Griffiths found space to cross from the left, which Moore failed to connect with but the alert Southam was able to stab into the unguarded net.
Not the end to the season Barnet would have wanted perhaps, but they did however come up against a Daggers side unbeaten in their last seven games.