Stevenage kept up their League Two play-off hopes with victory at fellow promotion chasers Oxford.
Boro took the lead in the first half when Luke Foster's cross found Harry Worley, who put through his own net.
The U's equalised in first-half stoppage time through Tom Craddock's spot-kick, after Peter Winn brought down Josh Payne in the area.
But Craig Reid latched on to Rob Sinclair's pass and coolly slotted home to give Stevenage victory.
Stevenage manager Graham Westley told BBC Three Counties Radio:"I thought the performance was very professional, very hardworking, very disciplined and very organised.
"We started the second half on fire, we got the ball down and worked it and what a finish from Craig Reid.
"Lawrie Wilson was outstanding all night. He was out of position but it was a monstrous performance."