Premier Division new boys Drogheda enjoyed an opening day win at O2 Park as Derry City went home empty handed.
New signing Mark Dempsey fired United in front on 11 minutes before Derry veteran Liam Coyle levelled from the penalty spot five minutes before the break.
But Drogheda weren't to be denied and Shaun Gallagher won it for Harry McCue's boys with a goal 20 minutes from the end.