Match gallery: Northampton 3 Chesterfield 1
Chesterfield boss Gary Caldwell says his side must keep believing in themselves if they are to avoid relegation.
The struggling Spireites are currently five points from safety after a 3-1 defeat at Northampton.
Northampton jumped into a 3-0 elead shortly after the break before David Faupala pulled a goal back.
But Spireites had no further answer as they slipped to yet another away defeat.