Mark Duffy's goal was enough to seal victory for Scunthorpe over Stevenage and put them three points clear of the League One relegation zone.
The midfielder cut in from the right-hand side after receiving the ball from Karl Hawley, before finding the far corner from the edge of the area.
Before the breakthrough, Hawley had seen his powerful header hit the bar.
Boro offered little going forward and failed to find an equaliser, falling to their fifth successive defeat.