Blues secured an impressive victory when the two sides met seven days earlier at the Arms Park and knew another win would again take them top of Pool 2 and keep qualification hopes alive.
A drama filled first half duly played out as Rhys Patchell, with a memorable 60-metre penalty, and Leigh Halfpenny kick Blues into a 6-0 lead as Warriors laid siege to the visitors’ line at times.
A tight and nervy second half saw Glasgow score a try with nine minutes left through Ryan Grant to set up a grandstand finale.
But Blues were not to be denied and a display of character and grit saw rewarded as they held out in dramatic late scenes to spark scenes of jubilation on the final whistle.
Blues looked to play with plenty of tempo in the opening minutes as Alex Cuthbert almost found an early gap after cutting back inside off his wing and Chris Dicomidis turned over ball and drove down the middle.
A penalty against the hosts, after they sealed off the ball at the breakdown, gave Rhys Patchell a huge attempt from way inside his own half. But he connected brilliantly with a monster 60-metre effort to put Blues ahead and warn Warriors they could not infringe anywhere.
An edgy opening ten minutes saw both outfits trade possession on a slippery surface as repeated knock-ons saw neither team able to build any momentum.
A penalty at scrum time against Glasgow gave Patchell another chance to kick deep into the Glasgow half. The driving lineout was set and Kristian Dacey looked to scramble on the floor before the ball was again lost in contact.
More solid work at the breakdown from Blues, picking up where they left off the previous week, saw referee Jerome Garces award a penalty to the visitors. This time Leigh Halfpenny took the kicking duties, but his effort drifted wide left of the target.
A big home scrum saw them awarded a first penalty of the night just before 20 minutes that Ruaridh Jackson looked to find a solid touch into a strong wind. Glasgow, tough, saw the lineout stolen by Blues and the attacking chance evaporated.
A high up and under from Lloyd Williams saw his opposite number Niko Matawalu spill the ball under pressure from Harry Robinson and when Blues went quickly a neat kick from Gareth Davies into the corner forced Glasgow back into their own 22.
The Warriors then made a further error as they were penalised for obstruction at the lineout to give Halfpenny a second chance that he this time duly nudged between the posts for a 6-0 lead.
Stuart Hogg’s break from deep and link up with Tommy Seymour looked to spark Glasgow into life. The home forwards carried strongly, despite appeals for a knock on in the build-up, before they went right but could not find a killer pass to unlock Blues as the ball was sent forward.
However, Blues were put under huge pressure on the resulting scrum close to their line and the referee had little choice but to award a Glasgow penalty.
The hosts sensed blood in the set piece and opted to scrum five-metres out with devastating impact as a series of penalties over five minutes saw a yellow card to Sam Hobbs.
Finally Glasgow did look to go wide, but Maitland spilled with the line at his mercy to the complete astonishment of the home crowd.
The winger, though, was reprieved by a knock on in the build-up by Filo Paulo, as he looked to intercept, and from the resulting play the defence was breached as Matawalu spotted a gap and swallow dived over.
But in yet more drama the try was then ruled out as Rob Harley took out Patchell off the ball and the referee, after consulting with his TMO, chalked it off.
Hobbs was back on for the start of the second half as Glasgow looked to make the most of the conditions with the wind now behind their backs as they adopted an expansive game.
Blues continued to put in the tackles and their bodies on the line while Robin Copeland exploded off the back of a scrum and Macauley Cook drove into men.
A quick tap penalty went badly wrong for Glasgow as Seymour was stripped of the ball by Cook. Blues piled forward with strong field position, but infringed as side entry at the breakdown let Warriors off the hook.
The game entered the final half hour with Glasgow looking to click into gear against a stubborn Blues outfit. Cuthbert ran from deep, after keeping a powerful kick in play with some neat handling above his head, and the visitors had to work hard to retain ball under big pressure.
Blues made a double change, as Ellis Jenkins replaced the hard working Rory Watts-Jones and Benoit Bourrust took the spot of scrum rock Taufa’ao Filise, on 55 minutes as boss Davies looked to keep his pack working hard all over the pitch.
Glasgow had a first shot at the posts on 58 minutes, as Blues were pinged for not binding, and up stepped Jackson only to drag his effort left of the uprights.
Warriors’ ploy of playing in their own 22 again could have backfired as Jenkins stole ball and Patchell burst into a defensive hole. The forwards immediately went to work and secured a penalty that Halfpenny slotted for a 9-0 lead with 15 minutes left.
Two quick-fire penalties saw Glasgow kick to the corner as they looked for a way back into the game. But the home hooker produced a bent throw to hand possession back to Blues.
However, a crocked feed at the resulting scrum handed ball back to the Warriors as nerves continued to build in Scotland.
Pressure was building and the hosts finally got the score they craved as a series of drives resulted in prop Ryan Grant crashing over for a converted try to cut the lead to 9-7 with nine minutes left.
The final few minutes saw Glasgow throw everything at Blues - with a late penalty by Weir flying agonisingly wide - before the visitors showed great composure to shut the door in the dying seconds as the final whistle sparked a huge celebration.
European dreams live on…
07m Patchell p 0-3
23m Halfpenny p 0-6
65m Halfpenny p 0-9
71m Grant t Weir c 7-9
Cardiff Blues: 15 Leigh Halfpenny, 14 Alex Cuthbert, 13 Richard Smith, 12 Rhys Patchell, 11 Harry Robinson (Davies 32-40), 10 Gareth Davies, 9 Lloyd Williams; 1 Sam Hobbs (Davies 76), 2 Kristian Dacey (Breeze 74), 3 Taufa’ao Filise (Bourrust 56), 4 Chris Dicomidis (Pretorius 66), 5 Filo Paulo, 6 Macauley Cook, 7 Rory Watts-Jones (Jenkins 55), 8 Robin Copeland
Replacements: 16 Marc Breeze, 17 Thomas Davies, 18 Benoit Bourrust, 19 James Down, 20 Ellis Jenkins, 21 Andries Pretorius, 22 Lewis Jones, 23 Dan Fish