O'Sulllivan leads charge against 10-man Longford
Longford Town 0 Cork Ciity 3
Longford Town manager Tony Cousins insisted a first-half red card for his teenage defender Tristan Noack-Hofman was a game-changer before Mark O'Sullivan came off the bench to provide the impact as Cork City made it seven league wins in a row at City Calling Stadium.
Victory keeps second-placed Cork four points off leaders Dundalk with the champions up next at Turner's Cross on Friday night.
Longford, without a win and a clean sheet since the opening night of the season, remain bottom, five points from safety.
Though Cork dominated possession, Longford held their own in a first half most notable for the sending off of 17-year-old Noack-Hofman on 34 minutes for a second yellow card.
Cork boss John Caulfield brought in O'Sullivan at half-time and he soon made the difference, flicking on goalkeeper Mark McNulty's clearance for Sean Maguire to put the visitors ahead on 57 minutes.
O'Sullivan doubled the lead on 73 minutes with a glancing header before midfielder Stephen Dooley wrapped up the scoring seven minutes from time.
Longford Town - Skinner; J Mulhall, Flynn, Rossiter (Gorman, 75), Noack-Hofman, Powell; Gannon, Dillon; Duffy (O'Hanlon, 65), Simon (Cowan, 70), O'Sullivan.
Cork City - McNulty; Healy (O'Sullivan, h-t), McSweeney, Bennett (Turner, 78), O'Connor; G Morrissey, Bolger (Buckley, 61); Beattie, Holohan, Dooley; Maguire.
Ref - Derek Tomney (Dublin).