Leinster do just enough to book place in Champions Cup semi-final
Leinster 18 Bath 15
Leinster squeezed into the Champions Cup semi-final with a gritty 18-15 win against an enigmatic Bath side who outscored their opponents two tries to one.
A kicking masterclass from Ian Madigan, who notched all his side's points, helped Matt O'Connor's men see off a spirited Bath side who sparkled in the Dublin sunshine with some thrilling running rugby.
George Ford scored and created his side's brace of tries in either half but Leinster managed to hang on in a compelling climax to edge through by the skin of their teeth and aided by the maximum return from their scrum.
Their greater experience ultimately saw them through but, with an away semi-final to come, they will have to be much better than this if they are to return to the final of Europan elite competition.
Ian Madigan opened Leinster's account just as the sunshine burst through with a 14th minute penalty.
The home side had attempted to play their scrum penalty advantage and, although the second of two Jamie Heaslip carries was just a couple of metres short, they consoled themselves with the three points.
Visiting out-half George Ford, thwarted already here with England this season, had a more difficult chance to level matters just three minutes later from wide on the right but he failed to cover the 50 yards.
The little magician, son of coach and former Ireland assistant Mike, responded brilliantly though with the game's first try as the game entered the second quarter.
It as a poor passage from play from Leinster, Madigan kicking poorly and then missing a first-up tackle - as did Mike Ross - as Bath pummelled the line with a superb carry from Francois Louw taking them to within a couple of yards of the try-line.
As Leinster were penalised, Bath were forced back to the other side of the field, some 30 yards behind the gain-line but, with the free play and more poor Leinster tackling, they soon piled on the pressure once more.
His conversion was another poor effort, though, smacking the bar.
Leinster responded positively, however, and a pair of Madigan penalties - in the 25th and 28th minutes - restored their advantage.
In between times, Anthony Watson was binned for a reckless attempt to contest a restart which left Rob Kearney pining in agony on the floor.
It was an exciting, open game albeit aided by a shed-load of mistakes from both teams; once Leinster reduced their number, they began to profit.
With Watson still in the bin and Bath's scrum offering up a second penalty, Madigan confidently knocked over his fourth three-pointer of the day for a 12-5 lead in the 34th minute and you felt that Leinster were one stride away from breaking free of their enigmatic opponents.
Even when Watson returned three minutes before their break, the indiscipline continued and this time Stuart Cooper transgressed at a lineout.
Heaslip once more beckoned Madigan to split the Havelock Square end posts and his inside centre once again obliged for a 15-5 lead that seemed much more comfortable than it actually was.
A late Fergus McFadden hit on the hapless Watson eventually roused an unusually subdued crowd which was well short of the official capacity.
Sadly, the stadium as silenced moments after the break when McFadden was knocked out after caroming into Kyle Eastmond's right shoulder just 51 seconds into the half.
Zane Kirchner came on and he almost scored in the corner before Rob Kearney was wide with a speculative long-range drop-goal effort.
Bath were retaining their commitment to running rugby and Ford once more cut Leinster's defence to ribbons in the 47th minute, jinking past Toner once more and feeding Hooper for the sublime score beneath the posts.
Against the run of play, Ford's simple conversion now reduced the margin to just three points - 15-12.
Matt O'Connor withdrew Mike Ross and his replacement Marty Moore helped Leinster win a scrum penalty with his first piece of action in the 52nd minute; Madigan converted from 45 metres to push his side 18-12 ahead.
Leinster's dominance at scrum-time afforded them even more breathing space.
Bath remained a counter-attack and, for the neutral, they were thrilling to watch and some of Luther Watson's counter-attacking was a sight to behold.
Peter Stringer came on to win his 100th European Cup with 15 minutes left as Bath continued to attack while Leinster desperately kicked possession away as they tried to retrieve territory.
With six minutes left, Bath's best work was being done too far out the field; when Leinster were penalised on their ten-metre line, Ford punished Sean O'Brien's transgression and now there was just a penalty goal between the teams.
Bath knew that their two tries would give them the victory once the sides finished the game level.
The visitors looked favourites to win against the flagging home side but, when Ford tossed a pass forward with his team threatening again, he tossed away his team's chance of progress.
Leinster advance, just.
Leinster: R Kearney; F McFadden (Z Kirchner 41), B Te'o, I Madigan; L Fitzgerald; J Gopperth, I Boss (E Reddan 58); C Healy (J McGrath 59), S Cronin (R Strauss 66), M Ross (M Moore 51), D Toner, M McCarthy (T Denton 72, J Murphy, S O'Brien, J Heaslip capt.
Bath: A Watson; H Agulla (T Homer 66), J Joseph, K Eastmond (S Burgess 61), M Banahan; G Ford, M Young (P Stringer 66); P James (N Auterac 53), R Webber (R Batty 50), K Palma-Newport (M Lahiff 58), S Hooper capt, D Attwood (M Garvey 63), C Fearns (A Faosiliva 58), F Louw, L Houston.
Referee - Jerome Garces (France)