|Glasgow Warriors (3) 9|
|Pens: Russell, Weir 2|
|Toulouse (6) 12|
|Pens: Bezy 4|
Toulouse completed a double over Glasgow to leave the Warriors with only a slim chance of qualifying for the European Champions Cup knock-out phase.
Four penalties from scrum-half Sébastien Bézy proved enough for the French side to gain the win that puts them firmly in charge of Pool Four.
Warriors responded through a Finn Russell penalty and two from his replacement Duncan Weir.
Glasgow and Bath trail Toulouse by six points with two matches to play.
The Scottish side need to win their final two games and hope other results go their way to avoid falling at the group stage once again.
Having gone down 19-11 in France last week, the Warriors knew they had to win to return to the top of Pool Four and maximise their chances of progressing to the knock-out phase.
And Gregor Townsend's side made a lively start and put some good phases together to pin Toulouse back in their own 22.
Henry Pyrgos' clever grubber kick just eluded Tommy Seymour, who would have been in for the try had he gathered the ball.
Toulouse opened the scoring through a Bezy penalty but, in an opening period punctuated by the whistle of referee Wayne Barnes, Russell responded with a three-pointer of his own to level things up, and nudged another kickable penalty just wide of the posts.
Bezy kicked Toulouse back in front on 20 minutes, but with both teams continuing to fall foul of the referee, momentum on either side was in short supply.
With the dangerous runners in both back-lines starved of decent service, the first half was largely a physical confrontation between the two sets of forwards.
Warriors full-back Stuart Hogg failed with a long-range penalty just before the break, and when Russell pulled a far more straightforward kick horribly wide early in the second-half, the groans around Scotstoun conveyed the concern among Warriors fans that their team was not producing the performance they had hoped for.
As was the case in the defeat in France last week, ill-discipline was now creeping into Glasgow's play, and Bezy punished them with another penalty to give four-time European champions a six-point cushion.
The Toulouse scrum-half successfully landed another kick to leave Glasgow staring down the barrel at 3-12 down with a quarter of the match remaining.
The visitors were not displaying the flair and attacking style associated with their vintage teams of years gone by, but their greater experience of big European matches was clear to see as they began to suck the life out of the Glasgow challenge.
Restricted to slow-ball from rucks, and the game seemingly going from set piece to set piece, the Warriors rarely looked like creating the openings to mount a comeback.
Substitute fly-half Weir nailed a penalty from 40 metres to bring the score to 6-12 with 15 minutes remaining, and when the same man struck again with the boot with seven minutes to go, the stage was set for a grand finale.
Niko Matawalu and Hogg looked to find the moment of magic Warriors craved with some elusive running, but handling errors and strong French defending extinguished Glasgow's hopes and left the Scots' hopes of qualification from the pool hanging by a thread.
Glasgow: Hogg, Maitland, Vernon, Dunbar, Seymour, Russell, Pyrgos, Grant, MacArthur, Welsh, Swinson, Gray, Wilson, Harley, Strauss.
Replacements: S. Lamont for Maitland (59), Horne for Dunbar (64), Weir for Russell (59), Matawalu for Pyrgos (59), Murray for Grant (53), Brown for MacArthur (70), Reid for Welsh (53), Nakarawa for Swinson (63).
Toulouse: Poitrenaud, Huget, David, Fickou, Medard, Doussain, Bezy, Steenkamp, Flynn, Johnston, Tekori, Maestri, Nyanga, Dustautoir, Picamoles.
Replacements: Lamboley for Poitrenaud (70), McAlister for Fickou (51), Kakovin for Steenkamp (52), Pulu for Johnston (69), Millo-Chluski for Tekori (75), Clerc for Nyanga (70). Not Used: Marchand, Palisson.
Ref: Wayne Barnes (RFU)