Dartford suffered their first defeat of the season in National League South on Tuesday night.
It was an unhappy return to Concord for Darts joint-boss Adam Flanagan, who quit as their manager at the end of last season.
Alex Wall - who Darts signed earlier in the summer only to let him go before a ball had been kicked in anger - scored the opener.
It took Wall only three minutes to make Dartford wish they hadn't released him just a week before the season started.
There appeared little danger for the Darts when Tom Bonner tracked Wall's run but his powerful right-foot shot stunned keeper Deren Ibrahim to give Concord an ealy lead.
Concord played some neat football at times but it was Dartford who created the majority of the chances in the first half.
All of Dartford's goals have come from set plays so far this season and it was easy to see why.
Delano Sam-Yorke twice went close before Ben Greenhalgh corners nearly created the equaliser, Billy Roast heading wide and then a scramble was cleared by Concord after another corner was only half-cleared.
Tyrone Sterling nodded over at the other end for Concord, while former Darts winger Ryan Hayes was kept quiet by Mark Onyemah.
It was a familiar story after the break as Greenhalgh fired a free-kick wide of the target.
Darts again enjoyed the majority of possession although chances were harder to come by.
Concord wrapped the game up on the break with 14 minutes left when Nana Boakye-Yiadom's deflected cross fell perfectly for D'Sean Theobalds to tuck home from close range.
Concord: Beasant, Clohessy, Shaw, Blackman (Smith 90mins), Pollock, Sterling, Hayes (Boakye-Yiadom 62mins), Green (Theobalds 62mins), Wall, Midson, Knott. Subs: Confrey, Littlejohn.
Dartford: Ibrahim, Driver, Onyemah, Roast, Vint, Bonner, Greenhalgh, Oyenuga (Cue 72mins), Murphy (Ighorae 67mins), Sam-Yorke, Bradbrook. Subs: Philpot, Isaac, Mensah.