Tony Grant hit a brace to inflict a fifth home defeat on the spin on Drogheda.
Bohs blitzed Drogheda with two goals midway through the first half.
Glen Crowe sidefooted home his 16th league goal of the season to put Bohs in front on 21 minutes.
Three minutes later Grant was put through to nab his first.
Grant then sealed the win on the hour mark as Bohs move four points ahead of Drogheda in third place.
