Jack Lester's first game as Chesterfield manager ended in defeat as Cheltenham won 2-0 at the Proact Stadium to record their first Sky Bet League Two away victory since February.
Mohamed Eisa scored in each half to see off a Chesterfield side who hardly created a clear chance in the game.
There was a three-minute stoppage early on because a leaking sprinkler left surface water on the pitch and Cheltenham almost put the skids under Chesterfield when Kyle Storer's 12th-minute shot was saved by Tommy Lee.
Jordan Flores volleyed wide for the home side who twice went close when Scott Flinders fumbled a corner in the 36th minute before a Flores drive spun off the goalkeeper and looped over.
Chesterfield were opened up in the 44th minute when Jerrell Sellars set up Eisa and the striker scored from the edge of the box.
And Cheltenham scored again in the 69th minute through another classy Eisa finish after substitute Danny Wright headed down a cross.