Jamie Devitt's second-half penalty was enough to earn in-form Carlisle a battling 1-0 win at Cheltenham.The result keeps the Cumbrian's play-off hopes alive as they made it eight matches without defeat.Cheltenham looked the more likely winners for long spells at a wet Whaddon Road, but Carlisle's backline stood firm.And in the 73rd minute, substitute Hallam Hope was brought down in the box and Devitt sent Scott Flinders the wrong way to seal the three points.It was the midfielder's 10th goal of the campaign.Jack Bonham saved early efforts from Mo Eisa and Jerell Sellars and Eisa saw another effort turned around the post by the Carlisle goalkeeper.Clint Hill handled the threat of Eisa well thereafter and the closest Cheltenham were to taking the lead was a looping header from Will Boyle which cleared the bar.After going ahead, Richie Bennett nearly made it 2-0 with a low show which beat Flinders' dive, but bounced back off the right post.Flinders also saved well from Hope twice late on as Carlisle finished the game strongly.