Grimsby Town's first win in 21 games saw them take a huge step towards securing their League Two place for next season with a vital 1-0 victory over Chesterfield.
The Mariners' first success of 2018 - and since Michael Jolley took over the reins - leaves them seven points clear of their opponents, who remain bottom of the table.
Mitch Rose kept his cool, under the most intense pressure, to score a decisive penalty two minutes from time. Given the magnitude of the game, it was a cagey opening 45 minutes but the visitors did enjoy a late wave of pressure.
Grimsby goalkeeper James McKeown denied Andy Kellett twice in quick succession, before making a smart save from leading scorer Kristian Dennis.
Upon the restart, Grimsby skipper Nathan Clarke went close with a header from six yards. A classic goalmouth scramble followed, with Luke Summerfield and Rose both being pegged back in the nick of time.
Chesterfield had forged the better opportunities before half-time, but it was a different story after the break. Drew Talbot was penalised for handball late on, with Rose stepping up to send Ramsdale the wrong way, sparking jubilant scenes in Cleethorpes.