Two goals from Omar Bogle helped the Mariners to ease past Aldershot at Blundell Park.
Charlie Walker pounced on Luke Oliver's header to give the away side a surprise first-half lead.
Omar Bogle levelled from the penalty spot after Richard Brodie fouled Toto Nsiala, before Padraig Amond found the corner to put the hosts ahead.
Bogle then missed a penalty but he netted his second before Nathan Arnold turned in the rebound from Bogle's shot to seal the win.