They scored twice in the opening 15 minutes and then held on despite Grimsby Town's second-half fightback when they reduced the arrears.
But Grimsby's lack of a big man up front was again evident and in fact, apart from the goals, neither goalkeeper was called seriously into action.
Mariners' boss Mike Newell was looking for a reaction after the mid-week 4-0 thumping from Dagenham, but Grimsby started in similar vein and quickly found themselves two goals down.
The first came on six minutes when Rob Purdie shot goalwards and on-loan striker Billy Clarke neatly back-heeled the loose ball into the net.
If that was not bad enough for Grimsby, who have now gone 22 league games without a win, things got even worse nine minutes later.
A corner was only half cleared and former Mariner Ricky Ravenhill volleyed home with a terrific goal from the edge of the box.
Grimsby were all at sea and could find no answer to Darlington's neat one-touch play.
But things did improve after Rob Atkinson, a young defender from Barnsley who was back on loan, went on to replace skipper Matt Heywood on 34 minutes.
Atkinson slotted in neatly alongside 18-year-old Ryan Bennett, who took the skipper's armband and they carried on where their partnership left off last season.
Grimsby's other loanee Jean-Paul Kalala had an equally impressive game back in Grimsby's colours and he gave the home side hope with a goal on 71 minutes.
The ball came into his path from midfielder Jamie Clarke and from the edge of the box his shot found the bottom corner with a slight deflection.
For the first time in the game the visitors were a little rattled as Grimsby pushed forward winning plenty of corners and throw-ins, but they just could not manage a second goal to earn a point.