FOURTEEN-MAN Louth produced an inspired second-half display to see off the challenge of a fancied Longford outfit in Haggardstown.
After a bright start by the visitors, Louth seized the initiative with a well-worked William Woods goal on 23 minutes, but disaster struck for Colin Kelly's side when midfielder and senior panellist Eoin O'Connor was sent to the line for a second bookable offence.
The hosts opened the second half with four points without reply before Cathal Bellew teed up Shane O'Hanlon for a sublime finish on 40 minutes.
Woods struck his second goal of the night to open a 10-point lead for Louth, 3-6 to 0-6.
It turned out to a be a crucial strike as Longford piled the pressure on their tiring hosts in the final 10 minutes but Robbie Smyth's injury-time goal came too late to rescue them.
Louth now meet Offaly in the semi-final at a neutral venue.
SCORERS-- Louth: W Woods 2-1, S O'Hanlon 1-0, B Rogan 0-2 (1f), E O'Connor, R Moore (f), B Hamilton 0-1 each. Longford: R Smyth 1-2 (2f), M Hughes 0-3f, P McCormack 0-2, J McGivney, D Mimnagh, C Clarke 0-1 each.
LOUTH -- J Flanagan; C Murray, D Campbell, T Hand; M Neary, P Reilly, C McEvoy; E O'Connor, S O'Hanlon; R Moore, C Bellew, P Kirwan; B Rogan, W Woods, B Berrill. Subs: B Hamilton for Berrill (h-t), A Williams for McEvoy (h-t), S McMahon for Hand (36), E O'Neill for Kirwan (54), S Reidy for Rogan (60).
LONGFORD -- P Collum; R Keogh, B O'Farrell, S Flynn; D Bennett, M Mulvey, D Cooney; P McCormack, J Keegan; D Farrelly, B McKeon, J McGivney; D Mimnagh, R Smyth, M Hughes. Subs: J Kelly for Bennett (25), C Clarke for J Keegan (48).
REF-- R Malone (Dublin).