City were left with a mountain to climb after going two goals down in the opening stages, and despite a spirited second half fight back they could not manage to leave the Capital with anything from the game.
Within the opening six minutes the hosts had the lead; Dwight Gayle beat McArdle for pace down the left hand side, his cross found Spillane whose shot was blocked and Billy Bingham was unmarked to power home the game's opening goal.
Dag & Red were undoing City in the final third with sharp, neat passing, and further chances fell to Bingham and Howell with The Bantams struggling to really forcefully attack the hosts.
On the half hour Dag & Red doubled their lead; Medy Elito received a return pass and had the pace to get away from Andrew Davies, his cross was dummied by Gayle before Spillane emphatically thumped the ball into the top corner from inside the area.
Will Atkinson tried to test Daggers' stopper Chris Lewington towards the close of the half with a volley and a deflected shot that went over and was saved respectively.
Bingham almost made it three after City were undone by neat passing once again; and his resulting curling shot from the edge of the area went narrowly wide of the target.
The Bantams started the second half brightly and James Hanson was inches away from scoring; Davies found Wells who crossed towards the big man, but he couldn't quite get a toe on the ball at full stretch.
With City looking the more likely to score the next goal, Dag & Red made it 3-0 from a corner kick; Elito's floated delivery was powered in by the head of the unmarked Luke Wilkinson.
Nahki Wells gave his side a glimmer of hope 5 minutes later, as he curled a superb 25 yard free kick over the wall and into the bottom corner to leave Lewington with no chance.
Three minutes later, The Bantams were awarded a penalty. The ball was on the move deep into Dag & Red's area and it eventually found Alan Connell at the back post who was sent crashing to ground by Lewington; the spot kick was clinically tucked away by Wells for his 2nd of the afternoon.
A few minutes later Wells was bundled over in the area after sneaking between two defenders; it looked a certain penalty but referee Mr P Gibbs waved it away despite huge appeals from the 349 travelling supporters behind the goal.
On the counter attack, Dwight Gayle raced through on goal between Oliver and Davies to drill the ball past McLaughlin and give his side a renewed two goal cushion.
With six minutes left Alan Connell pulled a goal back for City when he nodded in a bouncing ball at the back post after finding a couple of yards on the crowd of players in the area.
Despite stoppage time chances from Wells and Connell, Dag & Red held on to record three points in a 7 goal thriller and leave City three games without a win.