Patrick McEleney's goal midway through the second half gave Derry City the win which takes them three points clear at the top of the Premier Division.
McEleney backheeled the ball into the net from just a few yards out after home keeper Barry Murphy had saved Eamon Zayed's initial effort.
Two minutes earlier Bohemians thought they had scored but Aidan Price's header was disallowed for pushing.
Murphy saved well from Daniel Lafferty as Derry pressed for a second.
Derry are three points clear of champions Shamrock Rovers who have two games in hand.
Rovers are away to bottom club Galway United on Sunday.