Leinster withstood a spirited revival by French champions Biarritz to book a place in the semi-finals of the European Cup with a hard-fought 18-13 win here at Lansdowne Road.
Leinster were 13-0 up at the break but, come the finish, were clinging on desperately as Biarritz pressed for a game clinching converted try.
Cheered to the echo by 45,000 fans it took Leinster nearly half an hour to break the deadlock despite France flanker Serge Betsen being sent to the sin-bin for illegal use of the boot in the 14th minute.
Eventually, scrum-half Brian O'Meara's penalty gave Leinster a 3-0 lead in the 29th minute.
And he was involved again seven minutes later, his pass sending in flanker Keith Gleeson for a try from a ruck as the Biarritz defence froze.
O'Meara converted to make it 10-0 and although he missed a penalty attempt two minutes before the interval, right on the stroke of half-time he made amends to put his side 13-0 ahead. Biarritz's recovery began in two minutes after the break when France scrum-half Dimitri Yachvili kicked a penalty.
But it did not appear to be that significant a score as soon afterwards Leinster's Ireland back-row Victor Costello powered over from a five-metre scrum for an unconverted try.
And Leinster were inches from killing the game off in the 57th minute when Ireland wing Denis Hickie was tackled just short of the line by opposite number Philippe Bernat-Salles.
English referee Steve Lander called for video assistance and eventually ruled that France wing Bernat-Salles had just done enough to deny Hickie.
Yachvili doubled Biarritz's score with a 62nd minute penalty and there wa unexpected late drama when No 8 Thomas Lievremont scored a try converted by Yachvili deep into injury-time.
In a frantic final few minutes Biarritz pressed forward but could not score a second try.
Leinster will now face Perpignan in what will be the Irish province's first European Cup semi-final later this month.