Jim Bentley’s side made it two wins on the bounce for the first time since December last year as goals from Rhys Oates and Liam Mandeville earned them three points following Elliot Embleton’s early opener for the home side.
In truth it was a victory that Morecambe deserved as they passed the ball around neatly against a Grimsby side who had lost their last five games.
Michael Jolley’s Mariners looked nervous from the kick off.
The Shrimps created a great opening with only three minutes gone when A-Jay Leitch-Smith was played in behind a static defence but could only send his volley straight at James McKeown.
Moments later Andrew Tutte found himself in space on the right of the penalty area, with McKeown again coming to the rescue with a fine save at full stretch.
The Shrimps were rocked when Grimsby scored with their first meaningful attack. With nine minutes on the clock, good work by Jordan Cook saw him turn into space and find Embleton, who curled a shot past keeper Barry Roche from the edge of the penalty area.
It was the Mariners’ first goal in more than 500 minutes.
Morecambe continued to control the pace and Grimsby keeper McKeown again thwarted the excellent Tutte on the half-hour mark.
Grimsby struggled to worry the Morecambe defence but another long range shot, this time from Cook, did cause a few nervous moments and Roche was glad to see the effort dip just over the bar.
Morecambe hit back again before the break with Vadaine Oliver firing an effort over.
After the break, Martin Woolford shot straight at Roche before the Mariners hit the woodwork as Wes Thomas was unlucky to see his effort hit the underside of the crossbar and bounce to safety.
That seemed to be the piece of luck Morecambe have been looking for. On the hour, ex-Grimsby loan man Rhys Oates picked up the ball on the halfway line and waltzed through the home defence to drill a low shot past McKeown.
Four minutes later the Shrimps were in front when Mandeville’s left-wing cross evaded everyone and ended up in the bottom left hand corner of the Grimsby goal.
Grimsby: McKeown, Davis (repHall-Johnson 58) Hendrie, Whitmore, Collins, Woolford (Rose 68), Embleton, Welsh (re[ Pringle 68), Hessenthaler, Cook, Thomas. Subs (not used): Russell, Clifton, Hooper, Vernam.
Morecambe: Roche, Mills, Lavelle, Old, Conlan, Wildig, Tutte, Mandeville (Canston 83), Leitch-Smith, Oates (Piggott 89), Oliver (Oswell 81). Subs (not used): Halstead, Jagne, Hedley, Yarney.
Ref: C Sarginson. Att: 3,972.