Dean Cox's early strike secured Leyton Orient's first away win for almost two months at the expense of Stevenage.
Cox bundled home from close range after Boro failed to clear Leon McSweeney's cross.
Stevenage, who were playing for the first time in three weeks, had chances through Sam Hoskins and Felipe Morais.
In the second half, Orient's Charlie MacDonald headed over from close range and had a goal disallowed for offside while David Mooney also went close.
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Stevenage manager Gary Smith told BBC Three Counties Radio:
"We showed all the signs of a group of players who hadn't played in a while
"When we got into more exciting areas the choices weren't good enough.
"In many way's you've got to give credit to Leyton Orient, they defended well.
"The players are fully aware of how poor our form is here (at home)."
Leyton Orient manager Russell Slade told BBC London 94.9:
"I thought we defended very well. They are a big side but we managed to keep them out, and my goalkeeper wasn't troubled too much.
"Going forward I thought we were excellent and we created a lot of chances. The only disappointment was we didn't score more goals.
"We are turning into a very solid League One side and, if we add a little bit more, then we can only go forward."