It was the home side's first league defeat of the season, and although they had plenty of opportunities the Saracens white line was rock solid for 80 minutes.
Alex Goode scored the only try of the game from turnover ball, with Owen Farrell kicking 11 points.
Saints mustered penalties from Ryan Lamb and Stephen Myler, but their woe was compounded by injuries to Myler, Courtney Lawes and Dylan Hartley, which will concern England.
Freddie Burns made a mockery of his exclusion from England's autumn Test squad with an impressive performance as Gloucester extended their unbeaten Aviva Premiership record to six games with a 27-21 win over Leicester.
The Gloucester fly-half outshone opposite number Toby Flood - England's current number 10 - through a 17-point haul that included a superb solo try.
But Gloucester still had to dig deep in a gripping encounter, prevailing despite playing almost 10 minutes of the second period with 13 men after scrum-half Jimmy Cowan and full-back Rob Cook were sin-binned.
Tigers collected a penalty try in their absence, while Flood kicked 11 points and wing Scott Hamilton claimed an early touchdown, yet Gloucester deservedly triumphed through tries from Burns, wing Charlie Sharples and magnificent flanker Akapusi Qera.
Gloucester have not suffered a Premiership defeat since Northampton beat them on the league season's opening weekend, and they appear realistic title play-off contenders under rugby director Nigel Davies' assured leadership.
Leicester will feel they should have collected more than just a losing bonus point, given their relentless scrummaging supremacy, but Burns helped ensure it was not to be.
And the 22-year-old will surely be England's loss during their forthcoming autumn series after head coach Stuart Lancaster opted not to promote him from the Saxons squad.
Bath survived a remarkable second-half turnaround - and the bizarre dismissal of centre Dan Hipkiss while he was in the sin-bin - to claim the points against their West Country rivals Exeter in a nerve-tingling 23-15 derby victory at a sold-out Recreation Ground.
The Chiefs were outclassed in the first half as Bath ran in early tries by Ben Williams and Kyle Eastmond and could have gone in at half-time even further behind than 15-5.
But Exeter showed all their true character to fight their way back after the break and had Bath on the ropes until Stephen Donald opened up a 23-15 lead in the last two minutes of normal time. Even then, both sides went toe-to-toe for a full seven minutes of additional time in search of bonus points.