Andy Kellett scored an own goal as Chesterfield’s disastrous league away form continued.
Kellett’s unfortunate own goal came after Michael Bostwick had opened the scoring for Lincoln City.
Kristian Dennis netted his sixth goal of the season from the spot, but it was not enough for the visitors to take anything from their trip to the Imps.
The Spireites have failed to win on the road since March, 12 games ago, picking up just two league points away from the Proact since beating Swindon Town.
Despite the sacking of Gary Caldwell the struggling Spireites are still fragile at the back.
The mid-week English Football League cup with at Rotherham looked like it could have been a turning point.
But defeat at Sincil Bank sent the club back to the foot of the football league.
New boss Jack Lester named five changes for his second league game in charge of the Spireites.
Neither keeper was tested until Chesterfield conceded after 18 minutes.
The recalled Joel Anyon could not do much as Michael Bostwick’s shot deflected off Bradley Barry in to the back of the net.
And Anyon was equally as stranded for the second seven minutes later.
Kellett poked Harry Anderson’s cross in to his own net after the Imps’ man broke down the left before putting the ball in the box.
The Spireites almost pulled one back just before the break.
Jordan Flores forced a fine save from Josh Vickers from his goal-bound free-kick.
Chesterfield had to weather a storm early on after the restart.
Anyon did well to keep out Alex Woodyard with a really smart save after the midfielder burst in on goal.
Flores was on hand to clear Sean Raggett’s header off the line from the resultant corner.
And the rampant hosts could have had a third just before the hour when Ollie Palmer powered a header against the bar.
In the 62nd minute Bostwick nearly had a second with a header at the back post, with striker Chris O’Grady on hand with a last-ditch clearance.
Jordan Maguire-Drew missed a couple of chances to break his duck for the club, first heading wide before missing a volley.
Top scorer Kristian Dennis tried his luck from range, but could only strike wide himself.
With just nine minutes left Bradley Barry earned a penalty when he was barged over, with Dennis creating a nervy finish for the hosts by converting from the spot.
But the Spireites could not quite grab a late equaliser.
Lincoln City: Vickers, Eardley, Raggett, Dickie, Habergham, Anderson (Long, 89), Bostwick, Woodyard, Maguire-Drew (Whitehouse, 86), Green, Palmer (Ginnelly, 77).
Unused subs: Farman, Long, Waterfall, Arnold, Rhead.
Chesterfield: Anyon, Wiseman, Evatt, Barry, Kellett, Rowley (Mitchell, 77), De Girolamo (Dennis, 56), Flores, Weir, McCourt (Reed, 56), O’Grady.
Unused subs: Maguire, Briggs, Jones, Sinnott.
Referee: John Brooks