Lee Holmes scored one goal and set up another as Preston eased their relegation worries with a welcome win.
Holmes netted for just the second time this season when he curled in from 20 yards before crossing for Will Hayhurst to guide home the second.
Preston could have extended their lead but Jack King shot over from six yards.
Stevenage improved after the break but Robin Shroot fired over from inside the box before fellow substitute Steve Beleck headed wide.
It meant struggling Stevenage were condemned to a fifth consecutive away defeat as Preston moved seven points above the relegation zone.
VIEW FROM THE DRESSING ROOM
Stevenage manager Gary Smith told BBC Three Counties Radio:
"I thought we looked flat from the opening stages.
"We found it extremely difficult to get ourselves any sort of foothold in the game.
"Today we were second best for too long and they won the game in that period.
"It's now time for the players to really stand up and be counted. .I expect there will be a reaction on Tuesday [against Bournemouth]."
Preston 23 Rudd 04 Huntington 15 Connolly 16 Buchanan 26 Wright 08 Wroe 11 Holmes 19 Welsh (Mousinho - 85' ) 22 King (Beardsley - 67' ) 24 Hayhurst 29 Beavon Substitutes 01 Stuckmann 05 Robertson 17 Monakana 18 Procter 20 Beardsley 21 Mousinho 14 Garner Stevenage 01 Arnold 02 Gray Booked 04 Charles 14 Roberts 22 Comminges 06 Tansey 07 Grant 18 Mahon (Shroot - 65' ) 09 Haber (Beleck - 59' ) 15 Freeman 30 Hoskins (Akins - 59' ) Substitutes 16 Day 03 Hills 21 Iro 20 Jeffrey 32 Shroot 11 Akins 28 Beleck