Longford tasted defeat in the opening round of the Leinster U20 championship.
Louth scored a 4-16 to 1-15 in the group two opener in Darver. Early goals were the difference as Louth led 2-6 to seven points at half-time.
First-half goals from Adam Gillespie and Shane Lennon helping Louth to the first-half lead. Gillespie added another goal early in the second-half.
Michael Flynn found the Louth net two minute into injury time. However Louth landed their fourth goal a minute later, to win out 4-16 to 1-15.
Longford face Wicklow on April ninth in round three of the Leinster U20 championship.