Grimsby grabbed their first win in nine games to keep their First Division survival hopes alive.

Stuart Campbell headed home at the far post in the 76th minute - their first home goal of 2002 - to give The Mariners an important three points.

United were disappointing but could have stolen a late equaliser through substitute Phil Jagielka who headed narrowly wide from a Gus Uhlenbeek centre.

The Blades had the chance to take the lead after three minutes when Carl Asaba got in between Paul Groves and Danny Coyne but saw the keeper block his close range effort.

Michael Boulding then set up Bradley Allen whose right foot shot flew past the far post.

A United free kick from Robert Ullathorne was headed on by Asaba to Nick Montgomery whose fierce right foot shot hit the side netting.

United's Paul Furlong was booked for going in late on Groves before Grimsby's Wayne Burnett volleyed wide from a John McDermott cross.

Grimsby should have gone ahead in the 19th minute when Allen played Boulding clear.

But with only Simon Tracey to beat, Boulding hesitated and allowed Keith Curle to get in a tackle.

Coyne pulled off a fine save from Peter Ndlovu, arching backwards to tip over a left-foot volley in the 23rd minute.

Tracey was then well positioned to save a Campbell volley while at the other end, Coyne was beaten by a cross from Asaba which passed inches in front of the diving Montgomery at the far post.

Grimsby stepped up the pressure after the break and Boulding saw a snap shot rebound off Tracey's chest.

The keeper pulled off another fine save in the 59th minute, diving to his right to tip a Tony Gallimore free kick around the post.

Then, Paul Raven opened the attack and tried a cheeky back-heel which Tracey spotted late and smothered.

Intense Grimsby pressure finally paid off with 14 minutes to play.

Danny Butterfield's cross from the right was deflected to Campbell at the far post and he headed home.

Two minutes later, Jagielka beat Coyne with a firm header from Uhlenbeek's cross but the ball flew inches wide at the far post.

In added time substitute Paul Peschisolido looked set to score but Simon Ford got back to put in a vital tackle.

Teams:

Grimsby: Coyne, McDermott, Gallimore, Groves, Raven (Ford 64), Butterfield, Burnett, Coldicott, Campbell, Boulding, Allen.

Subs Not Used: Willems, Croudson, Jevons, Jeffrey.

Booked: Ford.

Goals: Campbell 77.

Sheff Utd: Tracey, Ullathorne, Montgomery (D'Jaffo 86), Page, Curle, Brown, Uhlenbeek, Ford, Furlong, Ndlovu (Jagielka 53), Asaba (Peschisolido 53).

Subs Not Used: Sandford, de Vogt.

Booked: Furlong.

Att: 7,141

Ref: A Leake (Darwen).