Saints produced a superb display as they beat Leicester Tigers 27-21 to win at Welford Road for the first time in more than 11 years.
Tries from Ben Foden, Cobus Reinach and Ahsee Tuala, allied with 12 points from the boot of the ice-cool Stephen Myler, got the job done for the black, green and gold.
Saints produced a defensive performance of real courage during the second half, securing their first league double over Leicester since the 2003/04 campaign and their first win at Welford Road since February, 2007.
They had come into the game on the back of a nine-try evisceration at the hands of Saracens but, for the second time this season, they bounced back from a huge defeat to the Barnet-based team by beating Tigers.
The win came despite an early injury to Rob Horne, who was forced off after just 12 seconds, heading straight to hospital after being knocked unconsious in a collision after chasing the kick-off.
Horne was knocked out by an inadvertent elbow to the temple from Sione Kalmafoni as his first outing as Saints captain ended in horribly rapid fashion.
The Australian centre was eventually stretched off after a lengthy delay, with Luther Burrell thrust into a much earlier than expected return from the bench.
Tigers won a penalty at the resulting scrum and started to crank up the heat on the Saints defence, which stood tall, with Tuala making a superb try-saving tackle on Adam Thompstone out wide.
And Saints were to be the ones who struck first as Paul Hill powered into enemy territory and after some patient build-up play and slick passing, Foden scored out wide.
Myler added the extras and he was soon notching a penalty as Saints' strong start continued.
But Tigers responded as some strong carries took them to within range and Ellis Genge offloaded for the onrushing Telusa Veainu to score.
George Ford converted to cut the gap to three points and Saints soon saw George North heading off for a brief time with blood pouring from his nose.
And Tigers were to go ahead when scrum-half Reinach had his box kick charged down by Graham Kitchener and Matt Toomua pounced on the loose ball to score.
Ford failed to add the conversion but Leicester led 12-10 with 10 minutes to go until half-time.
But Reinach was to quickly make amends for his error as he was set up by some fine play from a lineout by Teimana Harrison.
Reinach flew towards the line and stretched out an arm to score, with Myler adding the conversion to make it 17-12 at the interval.
And Saints started the second half in superb style with a scything run from Reinach setting up Tuala, who sidestepped his way to the line to score his team's third try.
Myler converted to make it 24-12 and Saints were then submerged under wave after wave of Tigers attacks.
Alex Waller, making his return from the bench after more than four months out, won a huge scrum penalty against the head to relieve some of the pressure.
But Tigers kept coming and after the TMO flagged up a high tackle from Harrison, Ford landed a penalty to reduce the deficit to nine points.
Saints desperately needed a prolonged spell of possession, but they couldn't get it and Waller was soon heading to the sin bin after a high tackle.
Ford kicked the penalty and Tigers trailed by just six points with 15 minutes to go and a man advantage.
But Saints responded with young prop Ehren Painter making a huge instant impact, winning a penalty at the scrum.
Myler kicked it and Saints led by nine points with 10 minutes remaining, but Ford responded with a penalty of his own just two minutes later.
Painter then did some superb work, getting over the ball to win a penalty after Tigers looked certain to score out wide.
But it was relentless stuff from the home side and they thought they had scored when Jonah Holmes dotted down.
But the TMO spotted crossing in the build-up and the try was not given, with Saints instead earning a penalty.
Leicester tried to ramp it up in the closing moments, but Saints stood tall, producing a mammoth defensive display to secure a win that meant so much to their supporters.
Leicester Tigers: Veainu; Thompstone (Holmes 66), Smith (Worth 65), Toomua, May; Ford, Harrison (B Youngs 56); Genge (Bateman 66), T Youngs (c) (Polota-Nau 56), Cole (Mulipola 60); Fitzgerald, Kitchener; Mapapalangi (Evans 66), Hamilton, Kalamafoni.
Saints: Tuala (Collins 66); Foden, Horne (c) (Burrell 1), Francis, North; Myler, Reinach (Mitchell 66); Ma'afu (Waller 52), Haywood, Hill (Painter 66); Ratuniyarawa (Paterson 79), Craig; Gibson, Harrison, Eadie (Nutley 74).
Referee: Matthew Carley