Leinster eventually found a route to the top of the Pro12 table, but a five-try total wasn't exactly the result of a five-star performance on a night not without its pitfalls against a doughty Dragons side.
Indeed, in almost the last action of the night, a red card for Franciso Chapparo for a fiendish spear tackle on Isaac Boss, will have sent shivers down the spine of watching Ireland coach Joe Schmidt.
Dragons held on to the ball for the first two minutes. They promptly turned it over without ever really going anywhere and, from a Leinster scrum penalty, the home side kicked for a territorial line-out close in.
Leinster were soon punching familiar holes, though and, with Rhys Ruddock and Jordi Murphy prominent, Dragons' difficulties on the floor allowed Ian Madigan to kick his side into a 15th minute lead.
Remarkably, the Welsh were tied at 3-3 before Leinster breathed some air; Jason Tovey, though, shouldn't have been able to slot a drop goal as Fergus McFadden's touch-finder was ruled out on the full, even though it clearly bounced in-field.
Dragons were wheezing. Jack McGrath made them wheeze more than most, blasting a huge hole on the blindside before, nine phases later, he swatted aside Rob Sidoli before slicing Richie Rees in two as he crashed over the line.
Madigan's conversion a minute before the break at least made the half-time tea taste a tad sweeter.
The Dragons suddenly played a different tune, albeit helped by Leinster being woefully off-key. Again, ruck ball was their downfall as the Welsh stung them with two sucker punch tries to turn 3-10 into 13-10.
Tovey then managed a penalty for 16-10 in the 53rd minute.
Despite their appalling breakdown efforts, Leinster roused themselves sufficiently by the hour mark to get back into Dragons' territory, back into contention and back into the lead.
Matt O'Connor, who had already hooked Shane Jennings, then slotted Jimmy Gopperth into the out-half berth as Leinster, belatedly, pushed for the winning post.
They did so, securing the five-pointer to boot, via a replica scrum with 13 minutes left on the clock. Dragons were reeling in every which way now, as Madigan's extras made it 24-16.
Leinster retired their front-row, Dragons retired their challenge and Darren Hudson added a fifth try.
Leinster: Z Kirchner; F McFadden, B Macken, N Reid (J Gopperth 61), D Fanning; I Madigan, E Reddan (I Boss 47 (D Hudson 80)); J McGrath (M Bent 68), S Cronin (A Dundon 71), M Moore (T Furlong 69), L Cullen capt, M McCarthy (T Denton 61), R Ruddock, S Jennings (D Ryan 53), J Murphy.
DragonS: H Amos (R Wardle 72); M Pewtner, P Leach, A Smith (R Wardle 53), W Harries; J Tovey, R Rees (W Evans 59); O Evans (A Coundley 66), T Rhys Thomas (S Parry 60), N Buck (F Chaparro 59), C Hill, R Sidoli capt (M Screech 59), L Evans, N Cudd, N Talei (J Groves 33).
Ref: M Mitrea (FIR).