Stalemate in Oriel
Cork City are disappearing out of sight at the summit as first draw of the season strengthened the Leesiders status in pole position.
The reigning holders are 15 points behind Cork after drawing 0-0 with a Derry City side that worked extremely hard at Oriel Park last night.
Kenny Shiels' well organised operation subdued Stephen Kenny's star men and they even had second half chances to nick a victory.
But there was always a sense that a scoreless outcome suited them. For Dundalk, it's yet another setback.
Ciarán Kilduff was introduced as a second striker, yet Derry arguably created the better chances as Dundalk fired blanks.
Seán Hoare came close to an own goal from a City corner with Robbie Benson's goal-line clearance coming to rescue and Barry McNamee and Nathan Boyle both threatened from close range.
Dundalk had more possession, but couldn't get close enough to deliver the killer blow.