Chris Ashton enjoyed a winning return to Franklin’s Gardens as Saracens took advantage of Saints’ injury woe to win 16-6.
Northampton, already without the likes of Ben Foden and Christian Day, lost England stars Courtney Lawes and Dylan Hartley as well as Stephen Myler during the 80 minutes.
And Sarries profited from Saints’ own production of Casualty, as Alex Goode’s try and 11 points from the boot of Owen Farrell saw them home.
Penalties from Myler and Ryan Lamb, starting again at 10, kept the home side in it but they were knocked off the top of the Aviva Premiership table as they didn’t have enough for victory.
All the pre-match focus had been on Ashton’s first return to the Gardens since his summer move to Sarries, but instead of taking the post-match headlines, he played his part in a fine team effort.
The away side soaked up punch after punch, and launched a number of dangerous counter-attacks, one of which resulted in Goode’s first-half try.
That put Saracens in the ascendancy and they never looked back, despite some determined attacking from Saints during the second 40 minutes, meaning Ashton and Co had the win they desired.
The match had started in frantic fashion with Saracens taking the early impetus and on seven minutes they earned a penalty on halfway, which Farrell slotted it to give his side the lead.
Saints were stunned into life and they started to make the ball stick as a good move, which involved most of the 15, resulted in a penalty that Myler kicked to level things up.
The home side were upping the tempo, and desire was coursing through the veins as the forwards started to get the green, black and gold on the front foot.
On 20 minutes, emotions nearly spilled over as Ashton smashed Vasily Artemyev into the boards after the Russian had kicked on and the home fans were baying for blood.
Referee Andrew Small refused to answer the calls, though it looked like blatant obstruction, and Lee Dickson made his feelings known, shoving Ashton and exchanging views.
Saints were showing all the necessary desire but they were failing to make territory count and Saracens launched a stunning counter-attack to retake the lead.
Fine work from centre Joel Tomkins was key in Goode adding the finishing touches in front of the Burrda Stand.
Farrell converted and to add injury to insult, Myler and Lawes were both forced off with knocks immediately after; Samu Manoa and Tom May on in their place.
The game continued to be played at 100mph, but Saints couldn’t turn pace into points as Saracens held their seven-point lead into half-time.
And Northampton were hit by a further blow at the break as captain Hartley was forced off with a foot injury, meaning Mike Haywood started the second half at hooker.
Despite the hat-trick of injury woe, Saints started the second half in determined style, forcing Saracens back and though they couldn’t quite get over the line, a penalty was awarded, allowing Lamb to bring his side back to within four points.
But Saracens didn’t waste time in restoring their advantage as Farrell was handed an easy chance in front of the posts, which he refused to pass up.
The away side were certainly not having it their own way in the second half, though, and referee Small was punishing them on a regular basis.
Saints’ scrum was standing tall, providing a good platform to build on, but still the elusive try wouldn’t come.
And Saracens looked set to get another score against the run of play as Tomkins latched on to a misplaced pass from Lamb and kicked through, but as the centre ran towards the line, he was overtaken by team-mate Ashton, who slipped and subsequently stopped his side from scoring.
But the men in white soon had the points they needed to take the possibility of a losing bonus point away from Saints, as Small awarded a penalty in front of the posts and Farrell again nailed it.
Jim Mallinder’s men continued to show fight until the final whistle, but Saracens shut up shop and knocked Saints off their Premiership perch.
Saints: Myler (May 28); K Pisi, G Pisi, Waldouck (Burrell 79), Artemyev; Lamb, Dickson (Roberts 79); Tonga’uiha (A Waller 62), Hartley (Haywood 40), Doran-Jones (Mujati 52), Lawes (Manoa 28), Sorenson, Dowson, Wood, van Velze (Oakley 74).
Saracens: Goode; Ashton, Tomkins, Barritt, Strettle; Farrell (Hodgson 79), de Kock (Wigglesworth 52); Gill, Brits (Smit 59), Stevens (Nieto 56); Borthwick, Hargreaves (Botha 59); Brown, Fraser, Wray (Joubert 52).
Replacements: Auterac, Wyles.
Referee: Andrew Small
Attendance: 13,475