Leinster's indifferent start to the RaboDirect PRO12 season continued with the Irish outfit beaten 23-19 by Glasgow.
Joe Schmidt's men have now lost two of their first three games of the new campaign as the struggle to adapt to life without many of their stars who are on international duty at the World Cup.
Leinster couldn't follow up their impressive showing against Newport last week, as Glasgow picked up a well deserved victory at the Royal Dublin Society.
The home side started the better and were off the mark after just two minutes when full-back Isa Nacewa, Leinster's man of the match against the Dragons last time out, kicked a penalty.
Glasgow missed a penalty of their own moments later, and after ten minutes, the game was yet to come alive, with both teams still finding their feet. Leinster were looking more dangerous with ball in hand, and were awarded a second penalty close in after good pressure, which Nacewa converted to leave it at 6-0 after the first quarter.
Glasgow responded well through a Scott Wight penalty and when captain Rob Harley dived over the try-line for the Warriors after a solid scrum, Wight added the conversion to leave the Scots ahead.
The home side added a try of their own before the break, when quick hands allowed Ian Madigan to score his second try in as many weeks, Nacewa adding the extras to leave it 13-10 at half time.
Both sides added two penalties apiece soon after the restart, either side of a lengthy stoppage for an injury to Leinster's Dominic Ryan, and a Rob Harley sin-bin for Glasgow.
The game was beginning to swing the Warriors' way though, and they added their second try of the game through Stuart Hogg, which was converted to leave them up by four with fifteen to play.
Leinster pressed hard for the remainder of the game, but couldn't quite get that all important winning try, and will have to make do with a bonus losing point, as Glasgow end the Irish side's 28-game unbeaten run at home.
Pens: Nacewa 4
Tries: Campbell, Horne
Cons: Wight, Weir
Pens: Wight, Weir 2
Yellow card: Harley (Glasgow)
Leinster: 15 Isa Nacewa, 14 Fionn Carr, 13 Eoin O'Malley, 12 Luke Fitzgerald, 11 David Kearney, 10 Ian Madigan, 9 Cillian Willis, 8 Leo Auva'a, 7 Dominic Ryan, 6 Rhys Ruddock (capt), 5 Devin Toner, 4 Kevin McLaughlin, 3 Jamie Hagan, 2 Richardt Strauss, 1 Heinke van der Merwe.
Replacements: 16 Aaron Dundon, 17 Jack McGrath, 18 Nathan White, 19 Damian Browne, 20 Jordi Murphy, 21 John Cooney, 22 Brendan Macken, 23 Darren Hudson.
Glasgow:15 Stuart Hogg, 14 Federico Aramburu, 13 Rob Dewey, 12 Troy Nathan, 11 Colin Shaw, 10 Scott Wight, 9 Henry Pyrgos, 8 Rory Pitman, 7 Chris Fusaro, 6 Rob Harley (c), 5 Nick Campbell, 4 Tom Ryder, 3 Ed Kalman, 2 Finlay Gillies, 1 Ryan Grant.
Replacements: 16 Pat MacArthur, 17 Gordon Reid, 18 Mike Cusack, 19 James Eddie, 20 Duncan Weir, 21 Ryan Wilson, 22 Colin Gregor, 23 Peter Horne.
Referee: Andrew McMenemy