Dagenham & Redbridge staged a remarkable second-half comeback to secure their League Two status.
Darlington took a 1-0 lead when Ricky Ravenhill's header hit the post and crept over the line and Mark Arber's own goal made it 2-0 after the break.
But sub Sam Sloma pulled one back from close-range and Dave Rainford's penalty made it 2-2 after Ben Parker was sent off for foul on Ben Strevens.
And Paul Benson's deflected shot from a tight angle completed the comback.
Make your League Two predictions
Darlington: Stockdale, Wiseman, White, Foster, Parker, Wainwright, Keltie, Ravenhill, Nelthorpe (Miller 71), Abbott (Reay 19), Wright (Cummins 55).
Subs Not Used: Kazimierczak, Kennedy.
Sent Off: Parker (64).
Goals: Ravenhill 20, Arber 52 og.
Dag & Red: Roberts, Huke, Boardman, Arber, Griffiths, Saunders, Rainford, Gain, Southam (Sloma 56), Benson (Nurse 82), Strevens (Moore 90).
Subs Not Used: Hogan, Taiwo.
Booked: Benson, Sloma, Huke.
Goals: Sloma 63, Rainford 66 pen, Keltie 74 og.
Att: 3,709.
Ref: Darren Deadman (Cambridgeshire).
~RS~q~RS~~RS~z~RS~38~RS~)