Cheltenham's hopes of moving out of the bottom four took a dent in the process as other results combined to sink the Robins further into the drop zone. Cheltenham actually made the better start to the contest and should have been a goal to the good after only four minutes. Keith Lowe's right-wing cross was headed down by Damian Spencer for Paul Connor to shoot from only a couple of yards out, but somehow Carlisle goalkeeper Keiren Westwood got his hand to the ball to divert it over for a corner.
Cheltenham goalkeeper Shane Higgs made a stunning save from a Paul Thirlwell drive two minutes later and Westwood had to save at full-stretch from a John Melligan free-kick as both goalkeepers showed their ability in the early stages.
However, Higgs was powerless when some hesitant defending gave Garner the chance to shoot on 15 minutes. Four Cheltenham players left the ball for each other 25 yards from goal and Garner nipped in to lash a powerful left-foot shot beyond the goalkeeper's outstretched hand.
After that Cheltenham huffed and puffed but failed to find a way past a committed and well-organised Carlisle team. Melligan battled manfully down the right-hand side but rarely found anyone to pass to and far too often the Cheltenham players gave the ball away too easily.
Carlisle, on the other hand, did a superb job of protecting their slender advantage by taking the ball into the opposition half and keeping hold of it with Johann Smith a constant threat down the left-hand side. Connor shot wide, Spencer headed wide and Craig Armstrong fired over the bar for Cheltenham, but they were all half-chances and Carlisle's excellent goalkeeper Westwood was able to mop up whatever came his way.