South African centre Pieter Muller's try with 12 minutes left secured the Blues their fifth league win of 2004.
Leinster (10) 18
Tries: Norton, Burke
Pens: Contepomi, O'Meara
Blues (12) 22
Tries: Muller, Appleyard, N. Robinson
Cons: N. Robinson (2)
Pen: N. Robinson
But Friday night's match at Donnybrook ended in controversy as visiting flanker Rob Appleyard was dismissed.
The Blues replacement was sent-off four minutes from the end for an elbow on Leinster back row Aidan McCullen who left the pitch in a neck brace.
The Irish province are without a win in five games and are now third from bottom of the Celtic League.
The Blues scored first half tries from Appleyard, on his first incursion on to
the field, and Nick Robinson with the outside-half adding a conversion for a
12-10 half-time lead.
Four minutes in, Argentinian centre Felipe Contepomi put Leinster 3-0 in front
from a close-range penalty.
On 19 minutes a loose scrum saw scrum half Ryan Powell scurry free and offload for
Jim Brownrigg to put Appleyard over for his second of the season.
Full-back Donovan van Vuuren found a gap to put Robinson over for his try on
38 minutes before Leinster full-back James
Norton coasted over in first half injury after a good break by centre Christian
Contepomi's conversion left two points between the sides and, six minutes
after the restart, a sure-footed Leinster attack ended with winger Brendan Burke
touching down in the corner for a 15-12 lead.
O'Meara's penalty bolstered the home advantage but a luckless Leinster conceded Muller's effort following a barnstorming
break from Canadian back row Dan Baugh.
Leinster: Norton, McWeeney, Warner, Contepomi, Burke, Leek, O'Meara, Bohan, Blaney, Brophy, Potts, Gissing, McCullen, Ronan, Dillon (capt).
Replacements: Lyne, Blaney, Kearney, Crawford, O'Riordan, Downey, Brown.
Blues: Van Vuuren, Vaughton, Allen, Muller, Morgan, Robinson, Powell, Fourie, Lewis (capt), Crompton, Quinnell, Brownrigg, Cockbain, Baugh, Sowden-Taylor.
Replacements: Fenton, Thomas, Senekal, Appleyard, Moore, Robinson, Walne.
Referee: Andrew Ireland (Scotland)