Chesterfield’s nine-game unbeaten run in all competitions came to an end as Halifax secured a late 1-0 victory in the Vanarama National League.
Robert Harker scored the decisive goal for the Shaymen in the 81st minute to dent Chesterfield’s promotion charge.
The Spireites, who will play West Brom in the FA Cup third round next month, are fourth, eight points behind leaders Notts County.
The first half lacked any clear chances and it took until the hour mark for either side to really threaten before Kian Spence sent an effort over the crossbar for Halifax.
Harker finally broke the deadlock with nine minutes remaining after reacting quickest to Matty Warburton’s free-kick, which was palmed away by Ross Fitzsimons.
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