It took less than a minute for Leinster to register their first score, and by 67 seconds the visitors held a 7-0 advantage, a lead they would never relinquish.
From the kick-off Kearney confidently claimed the high ball and set about the Dragons defence. His kick and chase had the hosts scampering backwards but it was a Leinster man who got to the ball to touch down for the game's first try through Cronin, converted by Ian Madigan.
Cronin, one of five Ireland internationals who returned to Leinster from Six Nations duty this week, is in something of a rich vein of form after also scoring two tries on his last club outing against Treviso, though once more a hat-trick evaded him.
At first, the Dragons offered an immediate response, Steffan Jones kicking a penalty from 35 metres out to close to within three points of Leinster after four minutes.
But that lead was soon extended as Cronin again earned a second try after fine play by the visitors who were keen to stretch the Dragons and use the width at Rodney Parade, though Madigan was this time unsuccessful with the conversion, leaving his side 12-3 ahead.
The hosts once again fought to close the deficit immediately, attacking their visitors from a successful lineout and breaking into Leinster's 22 to no avail.
After a series of scrums from which Leinster had the upper hand, Kearney increased their lead to 17-3 after strong work by the Irish province's pack, Madigan converting in the 20th minute as the game already appeared to be beyond the Dragons.
But it was from here that the hosts started to gain more possession. Around the half-hour mark Steffan Jones stood up to a big hit, and after playing advantage referee David Wilkinson took play back and Jones kicked three points from the resulting penalty.
Two minutes later, Steffan Jones and his teammates were dealt a blow when centre Jack Dixon was penalised and sent to the sin bin but Leinster failed to take advantage of their extra man as Jones played on when given another advantage and succeeded with a superb drop goal to move ten points behind at 19-9 adrift as the half-time whistle sounded.
Clearly buoyed from how they ended the first half, the Welsh region started the second with equal promise, and were soon back to within five points of Leinster as good work from the returned Dixon saw him hand the ball back inside to No.8 Ieuan Jones for the latter to touch down, though Steffan Jones blotted his personal copy book by missing the penalty.
Approaching the hour mark neither side could seize control with the visitors leading 19-14, but the hosts right back in it.
But third-place Leinster eased any nerves with their fourth try of the match when fine handling play in the Dragons 22 led to Kearney crossing for his second try of the match in the 65th minute, Madigan converting to move his side 26-14 ahead.
The hosts kept fighting until the end and Steffan Jones scored a deserved try of his own with a minute remaining, though he missed the conversion.
|Newport Gwent Dragons Score Card|
|Leinster Rugby Score Card|