Mark O’Sullivan and Gearoid Morrissey struck early and late in the second half, respectively, as Cork City firmly threw down a marker regarding their title credentials by beating Shamrock Rovers 2-0 at Tallaght Stadium.

Rovers’ players may have spoken during the week about how their 3-0 tanking at Turner’s Cross back in April made this a match they eagerly awaited in the hope of revenge.

But it was Cork who were the ones who came to Dublin showing greater intent.

This big win, their fifth on the spin in the league, moves Cork to within three points of leaders Dundalk with a game in hand.

Cork roughed Rovers up from the start with both Colin Healy and skipper John Dunleavy booked inside ten minutes.

It certainly had the affect of unsettling Rovers as Cork carved out the first opening on 12 minutes with Garry Buckley surging forward to fire just inches over the top with a 25-yard drive.

While not resting on ceremony in the tackle, Cork had come to play as well as they knocked the ball around the better of the two sides for much of the first half.

And they created another scorable opening on 26 minutes. Rovers failed to clear their lines to allow Billy Dennehy’s delightful dink pick out O’Sullivan who looped a header just over the bar with the ball landing on the roof netting.

Rovers did come alive to create the clearest chance of the half on 41 minutes.

Cork’s Republic of Ireland under-21 international full-back Brian Lenihan, who was watched by a representative of Wigan Athletic, was a little too easily outfoxed by Kieran ‘Marty’ Waters down the left.

The Rovers winger then also cut inside Darren Dennehy before bringing a decent parry save from Mark McNulty with a curling low drive.

Cork’s response was excellent, though, as they got forward immediately with Buckley shooting wide from inside the area.

The visitors remained the better side into the second half and got their due reward three minutes in with the lead goal.

Lenihan did well to get to the end line on the right to cross. Rovers were desperately poor in dealing with it and O’Sullivan turned on the loose ball to shoot home from just yards out for his sixth league goal of the season.

Rovers made changes, and finally began to make chances late on coming within inches of finding an equaliser on 81 minutes.

But Waters’ terrific free-kick came back off McNulty’s left hand post and arrowed out to safety behind the stranded keeper.

Darren Dennehy then made a goal-line clearance from Ryan Brennan’s header, somehow nodding the ball over the bar following Simon Madden’s cross.

But Cork stretched Rovers brilliantly on the counterattack five minutes into added time to score their second goal.

O’Sullivan set up Morrissey who drilled to the corner of the net to the delight of City’s travelling support.

Shamrock Rovers: Barry Murphy; Simon Madden, Conor Kenna, Jason McGuinness, Rob Cornwall; Shane Robinson (Robert Bayly 73), Ryan Brennan; Sean O’Connor (Eamon Zayed 57), Ronan Finn, Marty Waters; Ciaran Kilduff (Dean Kelly 64).

Cork City: Mark McNulty; Brian Lenihan, Dan Murray, Darren Dennehy, John Dunleavy; Colin Healy, Gearoid Morrissey; Liam Kearney (Dave O'Leary 64), Garry Buckley (John Kavanagh 76), Billy Dennehy; Mark O’Sullivan.

Referee: Derek Tomney (Dublin).