Chesterfield’s hopes of three wins in a a row for the first time since 2015 were ended by a goalkeeping blunder which gifted Stevenage a 1-0 victory at the Proact Stadium.
Aaron Ramsdale's attempted clearance hit Ben Kennedy and bounced in to settle a poor game.
Stevenage had the only chance of a first half devoid of quality in the 22nd minute when a Mark McKee free-kick was headed against a post by Danny Newton.
When the opening goal came in the 48th minute, it was through a dreadful mistake by Ramsdale who hesitated over his clearance which bounced into the net off Kennedy.
Chesterfield had their first effort on target in the 55th minute when a 25-yard free-kick from Louis Reed was turned over by Tom King and Joe Rowley had a shot deflected behind in the 63rd minute.
King was beaten in the 76th minute when Chris O'Grady glanced a header narrowly wide but Tom Pett was close to a second for Stevenage with a shot that rolled just wide in the 87th minute.