Carlow manager Turlough O’Brien was left to rue his side’s failure to hold on to a late lead as Monaghan ended their qualifier run.
After defeat to Dublin in the Leinster quarter-final, Carlow saw off London and Leitrim and were leading with 12 minutes to play in Cullen Park today.
However, Monaghan found their stride and pushed on for a five-point victory and a place in round 4B of the All-Ireland series.
O’Brien, whose side also beat Wexford in provincial preliminary round, told RTÉ Sport: "We gave it everything, we’d nothing left in the tank at the end of the game.
"I think Monaghan just got out by the skin of their teeth.
"We turned over a bit of ball towards the end and they got scores off it and that was the difference.
"I think we matched them all the way through and showed that Carlow can compete at the very highest levels.
"[The run has] been exceptional, we’ve been starved for all our careers, we’ve had no success and we were so close to getting through to the next round.
"[We got] fantastic support from around the county, everybody is so proud of the team. They are going to will it on next year to success."