Longford Town 0, Cork City 3 (full-time)
John O'Flynn hit a brace as Cork went top of the table ahead of Shelbourne on goal difference with a third successive win.
O'Flynn put City in the driving seat with the opener from a 14th minute corner.
George O'Callaghan added the second within three minutes of the restart when lobbing Stephen O'Brien.
A mistake by O'Brien gifted City their third goal on 55 minutes when his clearance from a Brian Byrne back pass hit O'Flynn to enter the net for the striker sixth goal of the season.