Lincoln boosted their play-off hopes and plunged Chesterfield deeper into relegation trouble with victory in a game which was halted while an air ambulance took a supporter to hospital.
The League Two game was stopped in the 26th minute so a helicopter could land on the pitch after a supporter required medical treatment in the East Stand of the Proact Stadium.
After a 30-minute delay, Alex Whitmore put Chesterfield ahead but Michael Bostwick and Scott Wharton headed the Imps in front before Ollie Palmer sealed victory.
Lincoln's physical presence troubled the Spireites and it needed a great save by Aaron Ramsdale in the 19th minute to turn a Matt Green header behind.
The game was held up when the air ambulance landed on the pitch after a fan was taken ill.
Shortly after the resumption, Whitmore headed in a Josh Kay cross to put the hosts ahead.
Lincoln equalised in the 45th minute when a corner to the back post was headed in by Bostwick but Jacob Brown almost restored Chesterfield's lead at the start of the second half with a 20-yard shot that Ryan Allsop just turned behind.
Another corner gave the visitors the lead in the 59th minute when Wharton climbed above Whitmore to head in and substitute Palmer sealed victory in the 85th minute when he went between two defenders to score from 12 yards.
Match report supplied by the Press Association.
