Kildare book semi-final date
Paddy Brophy struck for goals in the ninth and 15th minutes as the hosts kicked 2-4 without reply to lead at half time by 2-11 to 0-4.
Brophy added a point soon after the restart to put 13 between the sides but Louth reduced the deficit to five with 12 minutes remaining thanks to goals from Cian Doyle and Stephen Kilcoyne.