Farren hit the opener on 42 minutes from a swift counterattack. Gareth McGlynn and Ciaran Martyn worked the ball through for Farren whose first time shot from just inside the area beat Stephen O’Brien.

Peter Hutton’s free-kick was headed back across goal by Killian Brennan for Farren to double Derry’s lead on 68 minutes.

Barry Ferguson headed Longford back into it from Stephen Gough’s free-kick on 71 minutes but then got sent off for a second booking two minutes later.

Town substitute Dessie Baker was also sent off after the match for confronting referee Hugo Whoriskey.