Leinster eged the Border Reivers 35-34 in a nail-biting encounter at Netherdale on Friday night to move to the top of the Celtic League table.
Title-chasing Leinster made a powerful start and it was no surprise when they surged ahead with a try in the ninth minute from Jamie Heaslip.
Borders reacted in positive fashion to repair the early damage, Calum MacRae slotting two penalties in quick succession from close range.
But his strikes simply spurred the visiting forwards into more attacking action at the other end, with prop Ronan McCormack claiming the vital touch at the end of another unstoppable rumble.
MacRae completed his penalty treble with a superb 45-metre effort - only to see Will Green collect Leinster's third try straight from the restart.
Having missed his earlier attempts, Felipe Contepomi slotted the conversion, though MacRae hit back with another three points as the end-to-end action continued.
Contepomi replied in identical style, but the Reivers again rallied to carve out a touchdown for full-back Stuart Moffat, goaled by MacRae from the widest possible angle.
However, there was still enough time before the break for Contepomi to convert his own try to make sure of the precious bonus point for Leinster.
Borders refused to buckle and when MacRae added the extras to an opportunist score by Gregor Townsend, the match was back in the balance.
The frantic exchanges continued until the end with Contepomi adding a penalty and try for the Blues and Nikki Walker going over for the Reivers.
MacRae's fifth penalty set up a tense finale but the visitors held on to win by a single point.
BORDERS: Moffat, Danielli, MacDougall (King 70), MacRae, Walker, Townsend, McKearchar, McGee (Thomson 73), Scott, Douglas, MacLeod, Palepoi (Stewart 57), Dalziel, Brown (Miller 75), Gray (Sititi 75)
LEINSTER SCORERS: F. Contepomi (2 tries, 2 penalties, 2 conversions), J. Heaslip / R. McCormack / W. Green (1 try each)
15: Girvan Dempsey
14: Rob Kearney
13: Brian O'Driscoll CAPTAIN
12: Shane Horgan
11: Denis Hickie
10: Felipe Contepomi
9: Guy Easterby
1: Ronan McCormack (Emmett Byrne, 50)
2: Brian Blaney
3: Will Green
4: Bryce Williams
5: Malcolm O'Kelly
6: Niall Ronan (Cameron Jowitt, 57)
7: Keith Gleeson
8: Jamie Heaslip
Replacements not used:
David Blaney, Eric Miller, Brian O'Riordan, John Hepworth, Gary Brown
Referee: Neil Ballard (WRU)