Dave Rainford's penalty on the stroke of half-time saw relegation-threatened Dagenham edge past Wycombe.
Leon Johnson was penalised for handball after a goalmouth melee in first-half stoppage time and Rainford sent Frank Fielding the wrong way from the spot.
The hosts piled forward in the second half and Sergio Torres, John Sutton and Scott McGleish all missed good chances.
Visiting goalkeeper Tony Roberts produced a couple of stunning saves to deny Wycombe a way back into the game.
Wycombe: Fielding, Martin, Woodman, McCracken, Johnson, Bullock (Knight 58), Doherty, Holt, Torres, Sutton, McGleish.
Subs Not Used: Young, Stockley, Boucaud, Palmer.
Dag & Red: Roberts, Boardman, Uddin, Smith, Foster , Southam, Gain (Taiwo 90), Rainford, Griffiths, Taylor (Moore 67), Strevens.
Subs Not Used: Thompson, Sloma, Hall.
Booked: Gain, Moore.
Goals: Rainford 45 pen.
Ref: Rob Shoebridge (Derbyshire).