Two Jonny May tries saw Gloucester move above Northampton in the Aviva Premiership with a 27-11 win.
For so long a fortress, it was Northampton's third defeat at Franklin's Gardens in the league, and it was down to some magnificent Gloucester defence as Saints were twice stopped on the line and held up over it once, with the back-row duo of Sione Kalamafoni and Akapusi Qera superb.
May conjured a piece of magic in the first half and then pounced on a dropped ball for a 70-metre try for his second. Robert Cook contributed 17 points with the boot.
Phil Dowson scored Northampton's only try of the game in the second period, with Stephen Myler adding two penalties.