Chesterfield's play-off ambitions were dealt a huge blow on Tuesday night after they fell at home to League Two strugglers, Plymouth Argyle.
Two quick-fire, first-half goals proved to be too large a deficit for the Spireites to overcome and though they halved Plymouth's lead, Chesterfield could not find an equaliser.
Plymouth had the better opportunities of the opening 15 minutes, Conor Hourihane turned well inside the area but failed to beat Tommy Lee from a tight angle. This was soon followed by a Rueben Reid effort from outside the area that was just too high to trouble the Spireites 'keeper.
Chesterfield struggled to keep the ball and allowed Plymouth most of the early possession. The south-west team capitalised on their superiority as Joe Bryan put Plymouth ahead in the 21st minute, receiving the ball on Chesterfield's right flank before neatly cutting inside and curling a fine effort past Lee into the far corner.
Plymouth doubled their lead in the 26th minute. A mix-up in communication between Marc Richards and Lee resulted in a Neal Trotman header falling right onto the foot of Curtis Nelson who wasted no time in firing into the roof of the Chesterfield net.
Aside from a Jay O'Shea cross that narrowly missed everybody in the area and a Mark Randall free-kick that was beaten away by Jake Cole, the Spireites failed to create any real opportunities in the first half.
Chesterfield opened the second half brightly, with Conor Townsend beating two Plymouth defenders and firing a low ball across the opposing six-yard box only to see it deflected away for a corner.
Paul Cook made his first changes just ten minutes into the second half, bringing on Armand Gnaduillet for Richards and Alex Henshall for Richard Brindley.
The substitutions appeared to have an instant impact on the Spireites. Henshall rounded Plymouth full back Durrell Berry before firing across the Pilgrims area, the cross proved to be too much for Guy Branston, who deflected the ball into his own net.
Henshall continued to look lively throughout the second half and was a consistent threat on Chesterfield's left wing.
Plymouth were nearly gifted a late third goal after a simple Mark Randall pass deflected off the referee and consequently saw Andres Gurrieri one-on-one with Lee; however, the Pilgrims striker could only fire wide.
Chesterfield: Lee, Brindley (Henshall 55'), Townsend, Cooper (c), Trotman (Hird 72'), Darikwa, Togwell, Randall, Talbot, O'Shea, Richards (Gnanduillet 55').
Unused Subs: Barrington, Clay, Boden, Wafula.
Goals: (Branston OG 56')
Plymouth Argyle: Cole, Berry, Wotton, Branston, Bhasera, Cowan-Hall, Nelson, Hourihane (c), Bryan, Reid (Chadwick 81'), Gurrieri.
Unused subs: Gilmartin, Charles, Blanchard, Young, Murray, Harvey.
Goals: (Bryan 21', Nelson 26')
Referee: Mr Nigel Miller