Last year's Celtic League champions Leinster battled back to claim a draw against the side that finished runners-up.
An individual try by their new recruit from New Zealand Isa Nacewa put the Irish province ahead midway through the second half but a 55-yard penalty by Blues full-back Ben Blair levelled the scores and neither side could break the deadlock.
With the two teams having 100% records in pre-season matches confidence was high in both camps but it was the Blues who showed great adventure in the opening stages.
A Felipe Contepomi penalty put the visitors in front but most of the first period was played in Leinster territory.
The outstanding Maama Molitika made repeated inroads into the Irish defence but the Blues were unable to finish the moves off, although one overlap was only negated by a deliberate knock-on that might have merited more than a mere penalty.
The loitering Martyn Williams was presented with a loose pass by Leinster hooker Bernard Jackman and kicked to the posts but the chasing Nicky Robinson was unable to get past the large barrier formed by lock Malcolm O'Kelly.
The Blues maintained their pressure, however, and a long pass right saw Blair race over out wide for a try he converted himself.
Fly-half Robinson, in his 100th appearance for the Blues, popped over a drop-goal to end the session.
Defences had the upper hand in the third quarter with Leinster collecting two Contepomi penalties each side of another drop-goal by Robinson.
The Blues were still enjoying most of the possession but it was Leinster who grabbed the breakaway try to silence the passionate Arms Park crowd.
Nacewa, having switched to fly-half, launched a high kick which Blues winger Richard Mustoe failed to hold.
The loose ball cannoned back to the predatory Nacewa, who sped over from 40 yards. Contepomi converted.
Blair, who had missed a couple of straightforward kicks at goal, came good with a mighty effort from just inside his own half and it was all square again.
Nacewa showed his defensive abilities in tidying up after Blues number eight Andy Powell had charged down a clearance kick and another boot into the skies by the Fijian-Kiwi caused chaos as the Blues defenders left it to each other.
Fortunately the Irish side missed their opportunity when Rob Kearney sent his drop-kick wide.
After Ireland's heroic big-game hunt of the Springboks and Scotland's six-try runaround of the Pumas, the challenge of engineering the most spectacular win of the autumn series now falls on Wales, writes Peter Jackson.