Glasgow's bench took the strain as their replacements steered their side to a record-breaking seventh away RaboDirect Pro12 win in a row.
Away form continues to push the Scotstoun outfit into the play-off spots, with a place in the top four and a couple of games in hand because of called-off matches.
It had looked as though their record was going to disappear on Saturday at the same ground that Warriors' Heineken Cup hopes went up in smoke. They trailed 17-7 just after half-time, and were still 20-13 down going into the last 10 minutes. This time the substitutes played the dominant role with a new-look front five getting on top, back-rower James Eddie punching holes and outside-half Finn Russell exciting in attack and faultless in his goal kicking.
Certainly, the coach Gregor Townsend had plenty of reasons to thank the players who started the game in the stand. "The subs were excellent, all of them really lifted the pace," he said. "We needed to see a reaction in the second half and we did not really until the subs came on, so credit for them. We became stronger in the scrum and showed more urgency, which was pleasing.
"Our away record reflects very well on the character of the squad. They fight very hard for one another and relish going to away grounds to have to work even harder with the crowd and different environment. We have won all our away games in the league this season. It did not look like that at half-time, but it was a great effort from the bench."
Wing Lee Jones scored an impressive solo try in the first half, Russell landed two kicks to get his side back into the game and Eddie finished off a move he and Russell had set up. Finally Josh Strauss made a barging run into midfield to create space out wide, with Russell floating a long pass for centre Mark Bennett to score.
"We scored the try to level with about 10 minutes to go and went again from there," said Bennett. "We feel we have the squad to do it in this [RBS] Six Nations period. We have got a lot of guys away and you could say it is a weaker side, but it is a chance for the guys who are here to step up and make that shirt their own so it is not a case of the internationals just slotting back in.
"We reached the semi-finals last season so now w e want to be the first Scottish side to win something. We set that as the goal at the start of the season so that's our target and always has been. We've shown we have a squad here that is capable of that and willing to work towards it."
Cardiff had seemed in control after the opening try by Ireland squad member Robin Copeland from a Ruaridh Jackson error. Scrum-half Lewis Jones then added to their tally before the Glasgow substitutes made their decisive interventions.