The visitors had built a 10 point lead in the first six minutes through a try by Andrew Wilson and a conversion and penalty from Calvin Howarth.
However the Blues were soon into their stride with Lee Thomas slotting over a penalty – but Howarth soon negated this with his second successful penalty.
A burst of activity just before the interval saw the Cardiff side take the game by the scruff of the neck with two tries in quick succession. First Fereti Tuilagi got in for his first try since arriving from Leicester and then Kort Schubert crossed to give the home side a half time lead.
Alas the second half failed to live up to the excitement generated at the end of the first. Howarth knocked over two more penalties for Glasgow while Thomas collected three for the Blues – and Glasgow who were reduced to 14 men near the end after Eric Milligan was yellow carded – were unable to come back having to settle for the losing bonus point.