They were leading 4-0 and not even a last-minute consolation goal from Grimsby striker Gary Jones could spoil the Daggers' day.
They followed on from their midweek 6-2 thumping of Chester to make it ten goals in two games to ease their plight near the foot of the table.
For Grimsby, who last tasted defeat at home to Accrington on Boxing Day, they just could not get going at all from first minute until the last. They were tentative, sluggish and never matched the effort and aggression put in by the visitors.
The game was as good as over inside the opening half hour by which time Dagenham led 2-0.
A free header from Ross Smith put them on the way after 16 minutes and a controversial penalty given away by Grimsby's Jamie Clarke enabled David Rainford to put them 2-0 up.
Grimsby made two first-half changes and manager Alan Buckley played his last card by bringing on Peter Bore at the start of the second half.
There was a slight improvement and striker Danny North forced a tremendous save from experienced keeper Tony Roberts midway through the half which could have been a turning point.
But Dagenham always looked the more dangerous on the break and two late goals put them in dreamland.
Firstly top scorer Ben Strevens turned to make it 3-0 on 81 minutes and then a free header from a corner from Rainford completed the rout.
By this point many of the home fans had streamed out of the ground, so they did not see sub Jones pull one back in the last minute.
For Grimsby it was hardly the best of preparation for their Johnstone's Paint Trophy Northern Area final first leg at Morecambe on Tuesday.