Dean Morgan secured a 1-0 victory for Leyton Orient and ended Cheltenham's five-match unbeaten run.
Cheltenham pushed closer to the drop
Dean Morgan's first-half strike secured a 1-0 away victory for Leyton Orient and ended doomed Cheltenham's five-match unbeaten run.
Morgan fired Orient in front with his fourth goal of the season after 25 minutes when his crisp left-footed shot drilled into the corner past the despairing dive of Scott Brown.
Last-ditch defending by Michael Townsend denied Orient a second after the break, the defender clearing a Scott McGleish shot off the line and throwing himself at a Simon Church effort from two yards out.
Cheltenham manager Martin Allen made a double switch at half-time to inject some impetus into his side with youngsters David Hutton and Murray Watkins introduced.
Hutton made an impact and was only denied a 73rd-minute equaliser by a superb save from Jamie Jones, who tipped his shot over at the near post.
Cheltenham saw loud appeals for a penalty waved away in the final minute when Andy Gallinagh's cross was charged down by Jimmy Smith with his hands above his head.