Dave Rowson scored from 25 yards to earn Darlington all three points in a five-goal thriller. Wycombe, now winless in nine, took the lead on 11 minutes when Matt Bloomfield stroked home a pass from Tommy Mooney.
Neil Wainwright levelled on 26 minutes and then gave Darlington the lead with a stunning solo effort on 47 minutes.
Jermaine Easter equalised shortly afterwards, but Rowson struck to keep his own side's play-off hopes alive and severely dent those of their opponents.
Darlington: Russell, Wiseman, Collins, Phillips, Horwood, Wainwright, Cummins, Rowson, Prendergast, Joachim, Armstrong (Giallanza 63).
Subs Not Used: Stockdale, Johnson, Smith, Burgess.
Booked: Prendergast, Phillips.
Goals: Wainwright 26, 47, Rowson 70.
Wycombe: Batista, Martin, Stockley, Crooks, Bloomfield, Grant, Oakes, Palmer (Golbourne 54), Torres (Anya 75), Mooney, Easter (McGleish 69).
Subs Not Used: Young, Gregory.
Booked: Batista.
Goals: Bloomfield 11, Easter 50.
Att: 2,727.
Ref: N Swarbrick (Lancashire).