Defeat leaves them locked in fifth place and eight points adrift of reaching the play-offs with just three games remaining. And with Toulon in Marseille looming large on the horizon, Leinster face a potential doomsday scenario: season over by mid-April.
Head coach O’Connor said: “Qualifying for the play-offs is now almost definitely out of our hands. We’ve got three games remaining and will try to get as many points as we can out of them but now we have to hope other teams do us a favour.
“We have to find a balance between the league and Europe but that’s the dynamic at this time of the season and something we understand at Leinster. You have to make adjustments and can’t make excuses.
“We were relatively pleased with the first 50 minutes and pretty much in control of the scoreboard. But then we made errors and lost big moments. The yellow card [to try-scorer Ben Te’o] was massive.”
O’Connor was clearly caught between a rock and a hard place. Leinster knew they had to win this game to preserve league ambitions after watching the top four teams all win.
But the Toulon task is impossible to ignore and Leinster fielded just three of the side that beat Bath to set-up next week’s Champions Cup semi-final in Marseille; Te’o, Jimmy Gopperth and ick McCarthy.
O’Connor said: “We wanted players to put their hands up for selection. Some took their opportunity and others regressed.”
Those three survivors endured mixed fortunes against Dragons. Te’o was a constant threat yet Leinster’s lapses first allowed Jason Tovey to kick the opening points and then Dorian Jones to kick to the corner from where Rhys Thomas was forced over by his colleagues in the Dragons pack.
That fired Leinster. Shane Jennings failed to make it past the 13th minute, through a head injury, but the rest of the half was a constant surge of blue jerseys. Yet errors looked set to leave them frustrated before half-time.
Gopperth horribly sliced the chance to set up an attacking lineout, Jordi Murphy knocked-on and the scrum was penalised for wheeling just five metres from the Dragons line.
Yet Leinster were finally rewarded for their endeavour with two tries in the space of the three minutes before half-time that turned the game on its head.
Te’o combined strength and speed of foot to beat his opposite number and fend a second to touch down. Gopperth struck the post with his conversion but showed a clean pair of heels moments later, beating two defenders with a burst of a pace to cross.
The conversion on the stroke of half-time gave the visitors a 15-8 lead that few could deny them. And when Te’o brushed past two tackles to score a try out of nothing on 50 minutes, Leinster were cruising to a bonus-point win.
But a rash moment of indiscipline by Te’o, binned for striking Hallam Amos with his shoulder proved costly.
Taulupe Faletau got the Dragons back onto the front foot, bursting from a scrum for James Benjamin to score, before the British Lions No 8 blocked Eoin Reddan’s clearance for Benjamin’s second, six minutes from time, as Leinster tried to run out of defence.
Tries: T. Thomas, Dixon, Benjamin 2. Cons: Tovey. Pens: Tovey.
Tries: Te’o 2, Gopperth. Cons: Gopperth 2. Pens: Gopperth.
Tovey, Prydie, Morgan, Dixon, Amos, D. Jones, J. Evans, Price, T. Thomas, Harris, J. Thomas, Hill, Crosswell, Cudd, Faletau.
Meyer for D. Jones (54), Way for Price (58), Benjamin for Crosswell (43).
Kirchner, D. Kearney, Te’o, D’Arcy, Fanning, Gopperth, Reddan, J. McGrath, Strauss, Moore, Marshall, M. McCarthy, Ryan, Jennings, Conan.
Fitzgerald for D. Kearney (75), L. McGrath for Reddan (78), Bent for J. McGrath (75), Dundon for Strauss (52), Furlong for Moore (65), Molony for M. McCarthy (65), J. Murphy for Jennings (14).
Marius Mitrea (Italy)