Early tries from Jack Conan and Richard Strauss put the high-flying Irishmen, who are also the reigning Amlin Challenge Cup holders, in control of the league fixture after less than 20 minutes.
However, a superb finish from fly half Gareth Davies fired Blues back into the encounter and driving lineout score from the prolific hooker Kristian Dacey saw Blues battle back to 17-12 at the break.
Davies cut the lead to two points just minutes after the restart, but powerful Leinster surged once more and a try from Michael Bent sent them clear before Eoin Reddan grabbed the bonus point.
Blues continued to battle and were rewarded with a third try, this time by impressive full back Dan Fish in the week he signed new terms with the region.
But there was no consolation of a try bonus for the hosts, that would have been deserved, after a battling home show against a slick Leinster outfit.
Blues made seven changes to the line-up that was edged out late on by Glasgow with Josh Navidi returned after injury and Owen Jenkins, Gavin Evans, Gareth Davies, Lewis Jones, Sam Hobbs and James Down all called up.
Leinster also made changes with a completely new-look pack to the side that defeated Dragons while half backs Eoin Reddan and Jimmy Gopperth were recalled and Ireland international ace Luke Fitzgerald was named on the wing.
Blues looked to make an electric start with Robin Copeland handing off Noel Reid before Isaia Tuifua burst down the middle and rattled into contact.
There was, however, hearts in mouth as early as the second minute as fly half Davies had his kick charged down and only a knock on prevented an opening try for the Irishmen.
A huge Leinster scrum won a penalty on Blues ball and the visitors immediately opted to scrum. The ball spat out of the side as the hosts looked to hit back, but it was debut back row Conan who reacted first to touch down. Gopperth added the extras for a 7-0 lead.
A clash of heads in the tackle saw Owen Jenkins replaced by Tom Williams on six minutes and the utility back, who moved to full back, was immediately tested under a high ball that he managed to cling onto under pressure.
Leinster were slicking the passes around with real pace and invention, with Gopperth at the heart and orchestrating every move.
Tuifua turned over ball and then broke again down the middle with a barnstorming run. But one forced pass too many saw the ball spilled and Gopperth immediately kicked in behind to force Macauley Cook to race back and carry strongly into onrushing men.
Leinster came strongly again and after Eoin Reddan was just short with his dive for the line, after a neat show and go, the ball was recycled fast down the left wing where Fitzgerald applied the final pass to exploit the overlap with Strauss over.
Blues responded with slick handling almost sending Owen Jenkins over before the ball was pushed back inside for Scott Andrews and Sam Hobbs to punch holes that fly half Davies brilliantly exploited as he weaved his way over to reduce the lead.
Dan Fish pinned Leinster back in their own 22 with a well-judged drilled kick as the hosts started to try and work territory and possession after the initial burst from the Irish province.
Tuifua was impressing as he again broke the game line and showed his strength to battle past tacklers and rock the Leinster midfield back on their heels.
A penalty from Gopperth extended the visitors lead before Blues looked set to score a second try as Copeland pounced on a mistake from Reddan but was hauled up short just as the Arms Park crowd prepared to celebrate.
A sublime break from Fish saw him make 30 metres before Blues fired up field and came within inches of the score before a blatant infringement at the breakdown from Tom Denton to slow play down saw him yellow carded.
Blues immediately kicked to the corner and showed great patience with a driving lineout to blast over with Dacey touching down to reduce the lead to 17-12 before the break.
There was time for one more attack as again Davies sliced through a gap and fed the bulldozing Copeland on his shoulder as Blues threatened the Leinster lead before the interval as brutal hits started to fly in from both sides.
Blues came out all guns blazing at the start of the second half and opted to kick a penalty to the corner before Harry Robinson and the hard running Tuifua hurtled past men.
Another penalty this time saw Davies point to the posts and slot his kick to reduce the lead to two points. But a slice of fortune, after a horrible bounce from a chip, saw Gopperth nudge Leinster further ahead via the crossbar.
The Irish went further ahead on 52 minutes when a lost lineout fell for them and the forwards swarmed to drive up close before prop Michael Bent crashed over from close range.
Leinster sensed blood and a try bonus and that duly arrived on 56 minutes when sustained forward pressure opened up gaps and Reddan raced over to finish the game as a contest.
Blues refused to let their heads drop and opted to kick a penalty to the corner. Play was brought infield and Davies was again the man to exploit a gap as he tore into space before his pass out of the tackle freed Fish to dot down.
The home side continued to inject more and more pace into the game as they hunted a try bonus of their own.
But the hosts could not find the fourth try the home crowd craved and instead it was Gopperth who should have completed the scoring in the final minute only to drag his kick right.
Timeline:
05m Conan t Gopperth c 0-7
18m Strauss t Gopperth c 0-14
22m Davies t Davies c 7-14
28m Gopperth p 7-17
36m Dacey t 12-17
45m Davies p 15-17
48m Gopperth p 15-20
52m Bent t Gopperth c 15-27
56m Reddan t Gopperth c 15-34
61m Fish t Davies c 22-34
Cardiff Blues: 15 Dan Fish, 14 Owen Jenkins (Tm Williams 6-16, 76), 13 Isaia Tuifua, 12 Gavin Evans, 11 Harry Robinson, 10 Gareth Davies, 9 Lewis Jones (Ts Williams 68); 1 Sam Hobbs (Davies 57), 2 Kristian Dacey, 3 Scott Andrews, 4 James Down (Dicomidis 57), 5 Filo Paulo, 6 Macauley Cook (Hamilton 71), 7 Josh Navidi, 8 Robin Copeland
Replacements: 16 Rhys Williams, 17 Thomas Davies, 18 Patrick Palmer, 19 Chris Dicomidis, 20 Luke Hamilton, 21 Tomos Williams, 22 Simon Humberstone, 23 Tom Williams