A goal in the 2nd minute of added-on time by Dan Murray gave the Leesiders three vital points in their pursuit of Dundalk at the top of the table. The Hoops European challenge was dealt a blow in an overall disappointing game.
Despite the perfect conditions the game started slowly but John O'Flynn shot narrowly wide from outside the box on five minutes and two minutes later Kieran Waters could only head straight at 'keeper McNulty from close range following Luke Byrne's cross.
On 16 minutes Cork's Ross Gaynor was booked for a lunging challenge on Simon Madden and Sean O'Connor's free-kick fell to theback post but Conor Kenna's volley went across goal.
Kieran Waters speculative cross caused panic when McNulty slipped but the ball went just over the crossbar and nestled on the top of the net.
On the half-hour Kenna did well to clear from an attack down the Rovers right but the ball fell for Doherty and he fired a low shot on target but Barry Murphy did well to get down and beat the ball away.
In the 32nd minute Waters was fouled on the edge of the area and Stephen McPhail stepped up to take the free-kick and his low drive forced McNulty into a diving save.
The same player played Simon Madden in on the right-hand side of the box but he sliced his cross across goal and wide.
With two minutes remaining of the first-half Conor Kenna did well to stretch to clear an O'Flynn header across goal.
The start of the second-half continued with the overall scrappy play as both sides continually gave up possession. Kieran Waters strike on the hour did force McNulty into a very good save to tip the ball over the bar.
On 65 minutes O'Sullivan broke into the box on the left but good defending from Jason McGuinness denied him a shot on goal.
The best chance of the game for the home side came on 70 minutes when a cross from the left saw Healy get between the Hoops central defence but his header in front of goal went just wide of Murphy's right-hand post.
Karl Sheppard was substituted in the 74th minute but in the previous two minutes he did have two long range efforts in succession, the second of which forced McNulty into a diving save.
A sthe game neared the last 10 minutes Barry Murphy failed to punch clear a Gaynor free-kick but the Hoops cleared the danger while at the other end sub Ciaran Kilduff failed to make proper contact to O'Connor's cross from the right.
The home side pushed forward in search of a winner but it was only from dead balls that they caused any real danger to the Hoops defence with Healy and Gaynor providing the crosses.
As the game entered added-on time Kilduff raided down the right and his low cross found fellow sub Gary McCabe but his first-time shot from just outside the box sailed over the Cork goal.
[GOAL 1:0 - 90+2 min.] A late corner saw Healy deliver the ball to the back post and Jason McGuinness lost his battle with Dan Murray and the central defender gleefully headed into the net.