The result however on a blustery afternoon was rough justice on the Mariners who did more than enough to win. But they have now failed to score for six games and that is an unwanted club record.
But Grimsby should have ended that sequence when they were awarded a penalty in first half added time.
Man of the match Martin Paterson a handful all afternoon for Darlington was brought down inside the box for a clear penalty. Up stepped midfielder Ciaran Toner but his weak penalty was at a saveable height and keeper Lee Jones pushed it away.
That was the closest Grimsby came to a goal until the final seconds when an in swinging free kick by fullback Tom Newey was cleared off the line by Brian Close.
That just about summed up Grimsby's afternoon for they had dominated play but lacked a killer punch and to be fair rarely looked like scoring.
On a windy afternoon and a hard pitch good football was at a premium, but Grimsby did try to play what football there was and in Paterson they had an outstanding striker who on another day could have finished with a couple of goals.
For Darlington their only real threat came from nippy striker Julian Joachim and when he was brought down in the 81st minute it led to Darlington's goal.
The free kick was touched to defender Tim Ryan and his low shot somehow beat keeper Phil Barnes and nestled in the back of the net.
For Grimsby the alarm bells are well and truly ringing and their next two games see them travel to fellow strugglers Torquay and Boston which could go a long way to determining whether they can avoid the drop into the Conference for next season.