Lincoln City striker Marcus Richardson missed a great second-half chance to keep up the Imps' promotion chase.
The tall striker raced clear of the Cheltenham defence and rounded keeper Shane Higgs but then blazed the ball over the empty goal.
Cheltenham were good value for the goalless draw and were the better side in a tight first half.
Lincoln had the ball in the net for the only time in the game after just two minutes from a Peter Gain corner but referee Alan Butler ruled it out for a push on Higgs.
Cheltenham midfielder Dave Bird then tried his luck with a low shot on a wet pitch which Lincoln keeper Alan Marriott comfortably held.
Cheltenham midfielder Richard Forsyth then set up team-mate Grant McCann with a set-piece free-kick which he volleyed straight at Marriott.
Lincoln finally woke up and Higgs was forced to make a low save from Gain.
Veteran striker Bob Taylor saw a dangerous ball cross the Lincoln box without anybody getting on the end of it and then wing-back Brian Wilson set up Damian Spencer who just headed past the far post.
Lincoln improved after the break and referee Butler was forced to wave away a penalty appeal against Simon Yeo.
Richardson then missed the best chance of the game and Lincoln full-back Mark Bailey volleyed over.
Cheltenham soaked up the pressure and broke forward when Forsyth found Wilson whose left-footed shot was well saved by Marriott.
Cheltenham skipper John Finnigan, playing against his former side, nearly got on the end of a diagonal ball from McCann.
But Lincoln finished strongly and striker Gary Fletcher saw a dipping shot well saved by Higgs.
Imps' full-back Paul Mayo burst down the left and found Dean Cropper who was frustrated by Higgs.
Lincoln pushed forward right to the end and defender Ben Futcher volleyed over, but it was Cheltenham who looked happier with the result as they held on after three minutes of injury time.