Glasgow's quest to earn a lucrative home Celtic Cup quarter-final ended in frustration at Hughenden.
Glasgow: (3) 23:
Tries: R. Lamont, Parks
Cons: Parks 2.
Pens: Parks 3
Leinster: (13) 30:
Tries: Dempsey, Lewis, Gissing.
Cons: Holwell 3.
Pens: Holwell 3
Girvan Dempsey scored first for the visitors as they opened up a 13-point gap before Rory Lamont hit back for Glasgow after the break.
Dan Parks scored an interception try for the home side before Kieren Lewis crossed to restore Leinster's lead.
Parks slotted two penalties to bring Glasgow level only for Ben Gissing to notch Leinster's decisive third try.
Glasgow: Howarth, R. Lamont, Craig, Henderson, S. Lamont, Parks, Pinder, Tckachuk, Bulloch, Murray, Beardshaw, Turner, Swindall, Petrie, Dearlove.
Replacements: Lawson, Prescott, Hall, Beattie, Beveridge, Logan, Barrow.
Leinster: Dempsey, Brown, O'Driscoll, D'Arcy, Lewis, Holwell, Easterby, Corrigan, S. Byrne, Nebbett, Gissing, Cullen, Dillon, Gleeson, Costello.
Replacements: E. Byrne, D. Blaney, Crawford, Jennings, O'Meara, Contepomi, Quinlan.
Referee: Phil Fear (WRU)