Borders celebrated their Netherdale debut with their first competitive win, leaving the Celtic League champions almost certain not to qualify for the quarter-finals.

Centre Kevin Utterson was the key man, grabbing a first-half try, setting up another and landing a series of vital kicks.

Utterson drew first blood with a confidently-taken penalty in the fourth minute after the Irish were guilty of diving over the top in a ruck.

He put over another penalty before bursting through for the crucial opening touchdown.

Gregor Townsend created the time and space for Utterson with a half-break, allowing the centre to cruise in under the crossbar to give himself a simple conversion.

Brian O'Meara got Leinster off the mark with a penalty two minutes after the restart, but Borders were soon back in charge.

Townsend and Utterson helped Semo Sititi power through, Utterson adding the kick.

But then Borders were reduced to 13 men when Matt Taylor and Paul Thomson were sinbinned.

Leinster came back into the game with tries from John McWeeney and Ben Gissing, with O'Meara converting one and adding a penalty to cut the deficit to just two points.

But Utterson eased the jitters with another excellent kick to seal the points.

The Borders: T Vili, N Walker, K Utterson, J Stuart, C Moir, G Townsend, G Armstrong(capt), P Thomson, S Scott, B Douglas, D Weir, R Metcalfe, C Feather, S Sititi, M Taylor.
Subs: S Paterson, C Laidlaw, I Fairley, A Rennick, C Stewart, C Dunlea, S Gunn.

Leinster: C Warner, J McWeeney, K Lewis, S Horgan, G D'Arcy, A Dunne, B O'Meara, E Byrne, P Smyth (capt), N Treston, B Gissing, A Kearney, D Dillon, V Costello, L Toland.
Subs: P Coyle, G Hickie, A McCullen, S Jennings, S Keogh, M Leek/G Brown, D Quinlan.