A bright start for Dartford saw them take the lead in the opening 10 minutes from a low-driven strike from Josh Hill, played into his path by Tom Bonner.
James Dayton nearly levelled the scoring for Dulwich Hamlet after missing a fantastic opportunity in-front of goal in the 11th minute.
The Darts however nearly doubled their lead in the 28th minute, when George Porter was found through on goal and tried to take the ball around Charlie Grainger, forcing the number one to claw the ball away from Porter’s feet.
Ade Azeez had a good chance saved in the 58th minute, after a driving run from Keiran Murtagh opened up the opportunity to play the striker through.
Newly substituted Dan Roberts had the ball in the back of the net in the 68th minute, but was adjudged offside.
The home side struggled to get themselves back into the game in the second-half, with the only real chance coming from former Dart Darren McQueen – who hit the side netting in the 89th minute.
Former Dulwich player Tyrique Hyde sealed the victory for the away side in injury time, getting on the end of a loose ball into the box.
Dartford XI: 1. Dan Wilks, 2. Jordan Wynter, 3. Jernade Meade, 4. Noor Husin, 5. Josh Hill, 6. Tom Bonner, 7. Danny Leonard 65′, 8. Keiran Murtagh 79′, 10. George Porter 74′, 11. Jack Jebb, 14. Ade Azeez.
Substitutes: 25. Dan Roberts 65, 17. Connor Essam 74′, 16. Tyrique Hyde 79′
Dulwich Hamlet XI: 1. Charlie Granger, 2. Jazzi Barnum-Bobb, 3. Andre Blackman, 4. Michael Timlin, 5. Jack Holland, 6. Tyrone Sterling, 7. Deon Moore 59′, 8. Giovanni McGregor 71′, 9. Chike Kandi, 10. James Dayton 59′, 11. Darren McQueen.
Substitutes: 16. Jordan Green 59′, 17. Andrew Harris-Sealy 59′, 15. Danny Mills 71′