Grimsby racked up a third league win on the trot with a Martin Paterson brace.
The on-loan Stoke striker netted in the 38th and 72nd minutes to take his tally to four goals in three games at Town.
The first rounded off a superb passing move as Paterson played one-twos with Gary Jones and Nick Hegarty before curling a shot into the far corner.
Shrewsbury's Derek Asamoah hit the woodwork before setting up strike partner Michael Symes for a tap-in, but Paterson replied with a deflected shot.
Grimsby: Barnes, Croft, Whittle, Fenton, Newey, Till (Rankin 66), Pulis, Ravenhill, Hegarty (Harkins 60), Paterson, Jones.
Subs Not Used: Murray, North, Boshell.
Booked: Pulis, Fenton, Ravenhill.
Goals: Paterson 38, 72.
Shrewsbury: Shearer, Hall, Hope, Langmead, Herd (Cooke 75), Ashton, Drummond, Davies, Edwards, Asamoah, Symes.
Subs Not Used: MacKenzie, Thomas, Jones, Fortune-West.
Booked: Hall, Edwards, Ashton, Herd.
Goals: Symes 53.
Ref: T Kettle (Berkshire).