The game's only goal came from Cathal Brady who guided the ball into the net from a Carl Walshe cross eight minutes into the second half.
In those three games Derry have also failed to score.
No change at the top but the leaders both dropped points
Dundalk and Cork City were both held to 1-all draws after coming from a goal behind.
Dundalk remain 4 points clear at the top after coming away from the Showgrounds with a point against Sligo Rovers while Cork were left frustrated by Bray Wanderers at Turners Cross
Third placed St. Patrick's Athletic were unable to profit from the two sides ahead of them slipping-up as they were beaten 1-nil at home to Limerick FC.
Elsewhere, it finished 1-all between UCD and Athlone Town.
Meanwhile the derby clash of Bohemians and Shamrock Rovers was postponed shortly before kick-off.
The FAI say that the referee ruled that the pitch at Dalymount Park was unplayable.
A large divot in one of the penalty areas forced the match officials to rule that the surface was too dangerous for the players to play on.