Chris Cusiter (left) is tackled by Leinster prop Reggie Corrigan
Borders (13) 22
Pen: MacRae 4
Drop Goal: Jones
Gloucester (15) 19
Pens: Contepomi 4
A late Steve Jones drop goal secured Borders' first Magners League win of the season in a dramatic encounter with Leinster at Netherdale.
The visitors broke the deadlock with a Contepomi penalty before Borders replied with a Craig Hamilton try.
A MacRae conversion and penalty gave the home side the lead, but they were pegged back by a resurgent Leinster.
Stephen Keogh's try and further penalties from Contepomi looked to have won it before Jones' late strike.
The basement side Leinster took just two minutes to break the deadlock when Borders strayed offside and Felipe Contepomi slotted the penalty.
However, fears of a rout were quickly eased as Calum MacRae launched a thrilling counter-attack from which the Reivers eventually took the lead.
The full-back side-stepped two tackles before Scott Gray's grubber kick was brilliantly picked up by Craig Hamilton, who plunged over near the posts.
MacRae added the conversion before increasing the home side's lead with an easy penalty.
Borders belied their basement position as they continued to trouble their Irish opponents but the visitors reduced the deficit with a Contepomi penalty.
The Reivers hit back with a second MacRae penalty before Leinster turned the screw ahead of the break.
First, Stephen Keogh was driven over for a try, converted by Contepomi, before the Argentine's injury-time penalty gave the visitors an undeserved half-time lead.
Contepomi appeared to have put Leinster in control against a tiring Reivers outfit with his fourth penalty soon after the restart.
However, MacRae reduced the deficit following another infringement by Leinster before Cusiter sprinted 40 metres to take his side within metres of a second try.
But superb Leinster tackling kept them out and instead it took another MacRae penalty to level the scores.
Then, in a dramatic finale, Jones dribbled over the decisive drop goal to secure a memorable win.
Borders: MacRae, Robertson, MacDougall, Law, De Luca, Jones,
C. Cusiter, Kerr, Ford, Kalman, Palepoi, Hamilton, Beattie, Brown, Gray.
Replacements: Scott for Ford (74), Douglas for Kalman (58),
Dalziel for Beattie (40), Miller for Gray (75). Not Used: Newlands, McKearchar, Townsend.
Leinster: Kearney, Fitzgerald, O'Driscoll, D'Arcy, Hickie, Contepomi, Easterby, Corrigan, Blamey, Green, Hogan, O'Kelly, Jowitt, Heaslip, Gleeson.
Replacements: Lewis for Hickie (48), Willis for Easterby (21), Vermaas for Corrigan (58), Finnigan for Hogan (65),
Keogh for Jowitt (26). Not Used: Jackman, Warner.
Referee: Neil Ballard (WRU).