Monaghan strike late
The hosts sealed victory in the final quarter when they hit an unanswered 1-9 after Louth were reduced to 14 men following the dismissal of Declan Byrne (second yellow) after a foul on the impressive Tomas Freeman.
At the end of an open free-flowing first half Monaghan led 1-10 to 0-10 thanks to a goal from Christopher McGuinness in the 26th minute.