Manager Paul Groves put himself in the starting eleven at the expense of Ash Hildred who dropped to the bench. Wes Parker and Graham Hockless returned to competitive action following short term absences.
Hartlepool took the lead after just eight minutes. Town's defence stood and watched a Matty Robson cross allowing former Cardiff defender Andrew Jordan to head home past Andy Pettinger.
Jermaine Easter doubled the lead 10 minutes before the break. His clever touch took him away from the defence before he lifted the ball cleverly over the advancing Pettinger.
Town only came to life in the second half, Jevons the main threat although his finishing let him down on occasions.
It was Jevons who got the Mariners' goal on 60 minutes. His 30 yard freekick wrongfooted Dimitrios who expected his defence to clear.
Led on by Jevons, Town could have equalised with Gio Carchedi's diving header the best of several chances.
The defeat keeps Hartlepool top of the table on 16 points. Town remain in second, level on points with Scunthorpe.
Hartlepool: Dimitrios, Bass, M Robinson, Sweeney, Craddock, Jordan, Arnison, McCann, Easter, P Turnbull, Robson
Subs : Winter, N Wilkinson, J Wilkinson, Foley
Hartlepool Reserves 2 Town Reserves 1
Grimsby: Pettinger, Parker, Ward, Wheeler, Young, Groves, Hockless, Bolder, Mansaram, Jevons, Carchedi
Subs : Soames, Newton, Davey, Hildred, Nimmo
Subs : Soames, Newton, Davey, Hildred, Nimmo