Leinster moved clear at the top of Heineken Cup Pool One thanks to a hard-fought 19-7 victory over French champions Castres at the RDS on Saturday.
Jimmy Gopperth kicked 14 points as Leinster were made to work hard to overcome a spirited but indisciplined Castres side.
Gopperth kicked the home side into an early lead as he continued his impeccable recent form with the boot with three penalties in the opening quarter of the match.
That doesn't tell the full story though as both teams had opportunities to score tries in several spells of breathless rugby as they served up an entertaining start to the encounter.
Leinster perhaps had the better of the play in the early stages but the visitors hit back and they grabbed the game's first try just after the half-hour mark as Rory Kockott was the beneficiary of a simple blindside move from the base of a very strong scrum.
Number eight Antonie Claassen picked the ball up and fed the South African-born scrum-half, who sprinted down the left-hand touchline to score in the corner and he added the conversion to leave the score 9-7 at the interval.
Castres began the second half better as well and threatened to record a surprise away win for large periods but the game turned just before the hour mark as the visitors replaced their star man Kockott and centre Remi Lamerat was sent to the sin bin for tackling Dave Kearney into touch without using his arms.
The three-time European champions took full advantage as the outside backs launched an incisive attack down the right-hand touchline and replacement prop Jack McGrath was on hand to finish things off by picking the ball up and driving over the line.
Gopperth added some more breathing space with his fourth successful penalty of the afternoon and the win looked all but assured when replacement scrum-half Julien Tomas was sinbinned for repeatedly not putting the ball into the scrum straight with 10 minutes remaining.
Pedrie Wannenburg did come within millimetres of grabbing a losing bonus point for the Top 14 champions but he came up just short of the line in the closing stages and Leinster will be delighted to have emerged with the four points and a second consecutive win in the so-called 'pool of death'.
Pens: Gopperth 4
For Castres :
Yellow cards: Lamerat, Tomas
Leinster: 15 Rob Kearney, 14 Fergus McFadden, 13 Brendan Macken, 12 Gordon D'Arcy, 11 Dave Kearney, 10 Jimmy Gopperth, 9 Isaac Boss, 8 Jamie Heaslip (capt), 7 Sean O'Brien, 6 Kevin McLaughlin, 5 Mike McCarthy, 4 Devin Toner, 3 Martin Moore, 2 Sean Cronin, 1 Cian Healy.
Replacements: 16 Aaron Dundon, 17 Jack McGrath, 18 Michael Bent, 19 Quinn Roux, 20 Rhys Ruddock, 21 Eoin Reddan, 22 Ian Madigan, 23 Luke Fitzgerald,
Castres Olympique: 15 Brice Dulin, 14 Romain Martial, 13 Romain Cabannes, 12 Remi Lamerat, 11 Maxwell Evans, 10 Remi Tales (capt), 9 Rory Kockott, 8 Antonie Claassen, 7 Pedrie Wannenburg, 6 Jannie Bornman, 5 Rodrigo Capo Ortega, 4 Richie Gray, 3 Anton Peikrishvili, 2 Brice Mach, 1 Mihaita Lazar.
Replacements: 16 Marc-Antoine Rallier, 17 Karena Wihongi, 18 Saimone Taumoepeau, 19 Christophe Samson, 20 Ibrahim Diarra, 21 Julien Tomas, 22 Geoffrey Palis, 23 Daniel Kirkpatrick,
Venue: RDS, Dublin
Referee: Greg Garner