Elliott List's well-taken goal against the run of play saw Stevenage dent Harrogate's Sky Bet League Two play-off hopes with a 1-0 victory.
The midfielder converted a one-on-one to extend his side's unbeaten run to five games and leave Town six points shy of the play-off places.
The visitors dominated the first half and George Thomson came closest to opening the scoring when his deflected effort from a well-worked free-kick routine forced Jamie Cumming into a smart low save.
The closest Stevenage came was a Danny Newton effort that flashed wide of the near post after a flowing counter led by List and Elliot Osborne.
Harrogate were made to pay for missed chances seven minutes after half-time when List latched on to Cumming's long punt over the top and rounded James Belshaw to tuck home.
Undeterred, the visitors continued to create chances and Jack Muldoon twice blazed over the crossbar from close range, before heading straight at Cumming as Stevenage held on for three points.