Carlisle handed newly-promoted Grimsby their second 2-1 defeat on the bounce by edging their rearranged Sky Bet League Two meeting.
Owen Moxon opened the scoring with a stunning low drive, before Kristian Dennis came back to haunt his former club at Blundell Park. Michee Efete was on target for the home team after gift-wrapping Carlisle their second.
Grimsby midfielder Alex Hunt set his sights from distance in the early stages, but Carlisle soon found themselves ahead when Moxon let loose and beat goalkeeper Max Crocombe powerfully with a right-foot shot from 25 yards.
Hunt sent another strike wide midway through the opening 45 minutes, before jet-heeled Jack Stretton forced Crocombe into a decent save.
Grimsby went close through Otis Khan and Harry Clifton but, despite those two attempts, the away team soon doubled their advantage.
Dennis provided the finishing touch after Efete surrendered possession.
Efete atoned for his error by pulling a goal back for Grimsby, but while they pushed for a leveller – with Jordan Maguire-Drew going closest – Carlisle held on for the points.