Sam Jones struck twice to secure Grimsby a first win in five matches and deal a big blow to Blackpool's Sky Bet League Two play-off hopes with a 3-1 victory.
Danny Collins' header was cancelled out by Andrew Boyce's own goal as half-time approached, but the Mariners had enough time to retake the lead before the interval through Jones, whose 70th minute strike settled matters in the visitors' favour.
The first chance of the game fell to Blackpool after 13 minutes as Bright Osayi-Samuel broke down the left and his low shot from 12 yards was deflected inches wide of the far post.
But it was Grimsby who took the lead four minutes later, when Danny Andrew delivered a superb ball to the far post where ex-Sunderland defender Collins nodded home in front of the travelling fans.
The Seasiders were level after 42 minutes, in slightly fortuitous circumstances, as defender Boyce headed Andy Taylor's cross past his own goalkeeper James McKeown.
Parity did not last long however, as Blackpool failed to deal with a corner in first-half stoppage time and Jones stabbed Grimsby back in front from close range.
Jones grabbed his second after 70 minutes, when he pounced on a defensive lapse from Tom Aldred and raced clear before calmly slotting past Dean Lyness to seal the points for Grimsby.