Denis Hickie returned from injury to help himself to a hat-trick of tries, making him the leading try scorer in the Heineken Cup, as Leinster Lions cruised into the quarter-finals.
The home side ran in eight tries against Swansea in front of a packed house of 7,500 at Donnybrook.
Leinster opened the scoring with a Brian O'Meara penalty goal after just two minutes, but Swansea's reply was swift, Gavin Henson, preferred at No.10 to Arwel Thomas, slotting over his first penalty goal three minutes later.
Henson added a second three pointer after 28 minutes, and for a few moments it looked like the All Whites resurgence of recent weeks could continue in Dublin.
Shane Horgan was showing the form that made him an Ireland regular and it was his break after 31 minutes that set up Victor Costello to score Leinster's first try of the evening. O'Meara added the extras.
But then Colin Charvis was sin-binned after 34 minutes for killing the ball in the maul. And that proved the catalyst of Swansea's undoing. With the All Whites a man down, Leinster exploited the extra room, pulling Swansea across the park, and got their reward after 31 minutes when flanker Keith Gleeson scored the home side's second try, O'Meara missed the conversion but Leinster led 10-6.
The third try was added on the stroke of half-time by Ireland wing Hickie, and despite O'Meara's kick drifting the wrong side of the posts the home side went in 20-6 to the good at the break.
Henson continued his one man show in the second period, converting his own try and adding a penalty goal and a dropped goal to take the side's and his personal tally to 19 points.
But that proved to be the end of the Swansea scoring and with Hickie on the end of everything, Leinster sailed through. The pick of his tries came after 59 minutes when he collected the ball in the loose, spun around, broke two tackles and sprinted over from 22 metres.
Late tries from Aidan McCullen, Des Dillon and Gordon D'arcy wrapped up the result for the home side, were it not for O'Meara and Nathan Spooner missing seven conversions between them the home side would have easily broken the fifty- point barrier.
It ended 48-19 and Leinster can feel confident as they seal their passage to the quarter-final.
Leinster Lions 48 Swansea 19
HT: 20-6 Attendance: 7,500
Leinster Lions: Tries - D Hickie 3, V Costella, K Gleeson, A McCullen, D Dillon, G D'Arcy; Con- B O'Meara ; Pens - B O'Meara 2
Swansea: Try - G Henson; Con - G Henson; Pens - G Henson 3; DG - G Henson