Grimsby scored twice late in the first half to record a victory over Hereford.
Substitute Dayle Southwell opened the scoring after 40 minutes, firing into the bottom corner on the turn.
Four minutes later they had doubled their lead when Shaun Pearson scrambled the ball home after the Bulls failed to deal with Joe Colbeck's corner.
Hereford never looked like getting back into it and Brian Smikle headed wide, with Tom Nichols's shot being saved by away keeper James McKeown.
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Grimsby Town joint boss Paul Hurst told BBC Radio Humberside:
"We came down yesterday, prepared correctly and we looked to build on the Mansfield game.
"With the exception of an outstanding save at the end from James McKeown I didn't feel in too much danger.
"Credit to them, they did pass it well at times, but I thought we did it better today."