Cardiff Blues came away with two bonus points, as defending Guinness PRO14 champions, Leinster, opened the new campaign with a last minute victory.
The two European champions went head-to-head in front of a vocal 9,284 crowd at Cardiff Arms Park, as a new era under John Mulvihill got underway at the Welsh capital.
The Blues led by a single point at the interval following tries from Rey Lee-Lo and Jason Harries on his competitive debut.
And they turned on style in the second-half with the try-scoring duo completing a brace each to stretch the score to 29-14 and secure a bonus-point.
However, you could not write off the PRO14 and Heineken Champions Cup holders and they displayed their experience and ruthlessness to mount a comeback, thanks to a brace of tries from Bryan Bryne, either side of a score from Jamison Gibson Park.
Leinster put the pressure on Cardiff Blues early on thanks to the clever tactical kicking of Adam Byrne but the home team were up to task, notably when Jason Harries collected a cross-kick at full-stretch on his own try-line and managed to clear under immense pressure.
The Blues survived and following a thunderous hit in midfield from Rey Lee-Lo and a counter-attack from the Samoan at the next phase, they were awarded a penalty.
Jarrod Evans bisected the posts to open up an early 3-0 and it was soon extended with Lee-Lo centre of attention once again.
From a scrum mid-way through the Leinster half, Wales' Capital Region struck with Jarrod Evans receiving the ball on the loop from Willis Halaholo.
Evans sliced through the Irish defence and then put Lee-Lo away for the first try of the season.
With an 8-0 lead, Cardiff Blues appeared to have claimed a second try soon after following a rampaging from Seb Davies.
The athletic second-row was unable to put Lloyd Williams away but from the next phase Evans dinked a cross-kick to the corner. Owen Lane collected and crossed the whitewash but his effort was, perhaps harshly, ruled out for a double movement.
Ross Byrne hit back for the visitors with a penalty on 22 minutes and the reigning PRO14 and European champions continued to threaten, largely through their kicking game but also their ability to keep the ball alive.
They appeared destined to score as Fergus McFadden received the ball in plenty of space and with the try-line at his mercy, however Matthew Morgan raced across and threw himself at the wing, forcing him into touch with an immensely brave tackle.
Minutes later however, Leinster drew level as the Blues lineout miss-fired and James Tracey latched onto Lloyd Williams' pass as he desperately attempted to clear up.
Byrne struck the posts with the conversion but he nudged the visitors into the lead shortly after the half-hour mark.
The Blues reacted perfectly and dominated the closing stages of the half with numerous scoring opportunities.
First Harries was put in space on the right and just as he looked to put Lloyd Williams away the scrum-half was tackled without the ball.
The crowd were convinced referee Nigel Owens would go to the TMO to award a penalty try and yellow card but following consultation with the touch judge, Cardiff Blues were penalised for blocking.
Then Halaholo and Morgan combined with sleight of hand and fleet of foot to release Lee-Lo on the left but the centre dusted the touchline with his boot.
However, with half time looming, it was a case of third time lucky as Leinster fumbled a quick line-out outside their 22. Halaholo put the pressure on, with debutant Arhip on hand to pick up the loose possession.
The ball was quickly spread through the hand, with numbers lining up on the right, and Harries was on hand to take the final pass from Morgan and beat the final man to cross the whitewash on his debut.
Evans added the conversion, but Byrne added a further penalty for the visitors to make it a one-point game at the interval.
Harries started the second-half as he finished the first. With a try.
Lane created the opening as Leinster's defence jammed in and quick hands from Matthew Morgan released the wing. The former sevens star still had plenty to do but he demonstrated his impressive pace as he cantered home for a second try on debut.
Evans knocked over the conversion and three minutes later he was back at the tee as the Blues flying start continued.
They worked an overlap on left and Harries did remarkably well to sling the ball to Lane, who was tackled agonisingly short.
However, the damage was done and two phases later Lee-Lo was sent over for a second of his own to secure a bonus-point,
Evans once again added the extras to stretch their lead to 29-14 to send the Arms Park faithful into raptures.
Leinster responded on 55 minutes with Bryan Byrne the beneficiary after the Dubliners kicked to the corner and rumbled over.
Ross Byrne skewed his conversion wide as the scores remained 29-19.
Leinster were unrelenting as the fought to get back into the game but Cardiff Blues were more than a match with Evans and Morgan pinning them back.
But on 66 minutes, a superb touch-finder from Byrne after his side were awarded a bizarre penalty pinned the Blues onto their five-metre line.
Their driving lineout was held at bay but an intelligent kick-p from the base saw Jamison Gibson-Park cross at the posts.
Byrne converted the try to set up an immensely tense final quarter. Evans went some way to settling the nerves with a penalty on 70 minutes to make it 32-26.
Leinster continued to threaten but buoyed by the crowd Mulvihill's men forced mistakes. However, Leinster found time for one final attack, and despite phase-after-phase of commited defending from the hosts, Bryan Byrne eventually forced his way over, with Ross Byrne's straightforward conversion securing the win.