Gloucester extended their lead over Saints in the Premiership to five points
Two first-half tries by Gloucester wing Jonny May helped condemn Northampton to a fifth consecutive Premiership loss with a 18-16 win at Franklin's Gardens.
In difficult conditions it was Saints' Stephen Myler who struck first with a penalty before May seized the opening try, which Nicky Robinson converted.
Myler hit back with the boot again but May answered with an unconverted try.
Greig Tonks crossed for the hosts after the break to make it 13-12 but Robinson's boot ensured Saints' misery.
Amid a swirling wind and on a muddy pitch it was a misplaced pass that led to May's first blistering break, as he gathered a lose ball to slice through the Saints defence after Myler had given the hosts a three-point lead.
Robinson's conversion was answered by Myler's impressive kicking into a headwind which saw the scores brought back to 7-6 to Gloucester.
A break by Robinson fed a powerful run by Eliota Fuimaono-Sapolu who launched a speculative pass to the oncoming Olly Morgan.
The Cherry and Whites' full-back gathered on the bounce and passed inside to May, who crossed in the corner for his second try but Robinson's touchline conversion attempt struck the post.
Saints emerged for the second half rejuvenated and quickly took the lead when Myler's clever kick through found space in Gloucester's 22.
Tonks was first to react and the full-back scooped the ball before diving over under the posts to set up an easy two-point kick for Myler.
But the stand-off spurned a chance to extend his team's lead by another three points when his penalty attempt missed.
Robinson landed two more penalties before the hour mark and even the appearance of England lock Courtney Lawes, back for his first game since 8 January, could not help Saints and Gloucester began to dominate.
The visitors, inspired by the return of their own England second row Dave Attwood after a nine-week ban, produced a series of phases to run down the clock.
Myler landed another penalty, awarded from a scrum, to give Saints hope but after a driving maul was pulled down in front of the hosts' posts with just minutes left it looked to be all over.
Gloucester went for the line-out but knocked on and despite a desperate final flurry by Saints their fate was sealed.
Northampton director of rugby Jim Mallinder: "We are still confident and hopeful of making the top four.
"We've got to be tighter in defence and sharper in attack, we've lost a bit of confidence.
"We were playing well through the autumn internationals, so we cannot use the Six Nations as an excuse.
"I had hoped we would continue the composure we showed at the start of the second half, but we gave away weak, stupid penalties and that stung us."
Gloucester head coach Bryan Redpath: "It's a massive statement of intent but I'm aware of where we are and aware of where they are too.
"We're doing the basics well, not getting too panicky, worrying, or getting over excited and carried away.
"I thought we handled the conditions very well in the first half, Nicky kicked well and we took two opportunities that came our way.
"Sometimes you tend to panic and kick the ball away in wind like that, worrying too much about territory but I thought we balanced that well in the first half."
Northampton: Tonks; Reihana, Clarke, Downey, Diggin; Myler, Powell; Tonga'uiha, Sharman, Mujati, Vickerman, Sorenson, Clark, Dowson, Easter. Replacements: Geraghty for Tonks (77), Glynn for Powell (77), Waller for Tonga'uiha (77), Lawes for Clark (52). Not Used: Long, Mercey, Day, Armstrong.
Gloucester: Morgan; May, Molenaar, Fuimaono-Sapolu, Voyce; Robinson, Pasqualin; Wood, Azam, Doran-Jones, James, Hamilton, Buxton, Qera, Narraway. Replacements: Trinder for Molenaar (54), Robson for Pasqualin (66), Attwood for James (61), Strokosch for Qera (54). Not Used: Dawidiuk, Thomas, Harden, Burns.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.