Kevin Sainte-Luce came off the bench to score a late goal for AFC Wimbledon and fire them out of the relegation zone.
The Dons started brightly and Gary Alexander was denied by a superb point-blank save from keeper Chris Lewington.
After the break Dagenham came close to an opener when Matt Saunders fired in a shot from 18 yards which whistled past the angle of the post and crossbar.
But with 10 minutes left Sainte-Luce was on hand as he rifled home low from 25 yards to secure a priceless victory.
VIEW FROM THE DRESSING ROOM
AFC Wimbledon boss Neal Ardley told BBC London 94.9:
"We didn't look in too much trouble and was an all-round fantastic team performance.
"We worked hard and we are fitter and stronger. There is a belief in the players and the momentum we are creating meant I had belief we would get something today.
"Our support have been phenomenal and I hope they go and have a beer. We must stay focused as this league is unforgiving."