Derry City 2 Mervue United 0
Mervue's hopes of a shock ended early as Derry took a 16th minute lead when Padraig Moran headed home a Gareth McGlynn cross.
Derry then sealed their less than comfortable win on 67 minutes with an albeit fully deserved second goal.
Gary Beckett whipped over a cross from the right and Eamonn Doherty headed home at the near post.