Saints moved back to the top of the Gallagher Premiership table after producing a sensational derby-day display at Franklin's Gardens.
The black, green and gold cut local rivals Leicester Tigers to shreds, with All Blacks centre Matt Proctor scoring twice on his Premiership debut.
There were further tries from Api Ratuniyarawa, Tom Collins and Fraser Dingwall in a hugely dominant 36-13 success for Chris Boyd's confident side.
It sent the Gardens into delirium as the Saints supporters revelled in their team's ruthless showing, while enjoying the lack of a Leicester response.
Only a Guy Thompson try and eight points from the boot of George Ford gave Tigers anything to shout about as they endured more misery against Saints.
Chris Boyd's men have now won both East Midlands meetings this season and four in a row in all competitions.
And they did it in style at the Gardens on Saturday afternoon, with the likes of Rory Hutchinson, George Furbank, Taqele Naiyaravoro and James Grayson pulling Tigers apart at the seams.
Grayson was one of three changes at late notice prior to the game as Owen Franks, Courtney Lawes and Dan Biggar were forced to withdraw due to injury.
And it didn't get any better when the game started as full-back Furbank was forced off for a head injury assessment inside just four minutes.
After a scrappy opening 12 minutes, Tigers took the lead as Mike Haywood was punished in front of his own posts and George Ford did the rest.
Furbank was then able to return as Saints tried to turn the screw in the Tigers 22, and they scored an easy try as Cobus Reinach grabbed the ball from a scrum and sent Proctor over.
Grayson converted to make it 7-3 and Tigers soon lost wing Jonah Holmes to injury.
But Tigers bit back, winning penalty after penalty in Saints territory before flanker Thompson forced his way over.
Ford added the extras and his team were back in front at 10-7 up.
Saints were soon level through a Grayson penalty after a high tackle on rampaging prop Alex Waller, who had burst into the Tigers 22.
Leicester were looking to respond, but it was Saints who were to score their second try, and in some style.
Furbank and Hutchinson produced some brilliant handling and Proctor was on hand to spin and score in the corner.
Grayson converted from the touchline and he was soon bending another ball between the posts after another sensational Saints move that saw Hutchinson, Proctor and Naiyaravoro combine to send Ratuniyarawa over the line.
Saints were 24-10 up at the break, knowing one more try would bring them the bonus point.
But Tigers were first on the board after the restart, Ford landing a penalty after Alex Moon had been sin-binned for deliberately slapping the ball out of Leicester hands.
It didn't disrupt Saints' momentum though as Leicester continued to throw lineouts away, leading to Tom Wood pouncing before Reinach sent a superb pass out to Collins, who was waiting in acres of space to score his team's bonus-point try.
Grayson missed the conversion but Tigers were now really struggling to respond, failing to get any meaningful possession or territory.
And it was about to get even better for Saints as Dingwall finished off another flowing move, just seconds after he had replaced Proctor.
The Saints fans were loving every second of the East Midlands massacre, with chants ranging from 'who the **** are Leicester Tigers?' to 'can we play you every week?'.
The hosts continued to pile on the pressure, and the agony, as the game reached its conclusion.
Tigers struggled to get out and eventually went home with their tails between their legs as Saints celebrated a hugely impressive success.
Saints: Furbank (Tuala 66); Collins, Proctor (Dingwall 70), Hutchinson, Naiyaravoro; Grayson, Reinach (J Mitchell 72); Waller (cc) (Van Wyk 65), Haywood (van Vuuren 70), Painter (Hill 65); Moon, Ratuniyarawa (Coles 68); Wood (Gibson 68), Ludlam, Harrison (cc).
Leicester Tigers: Worth; May, Tuilagi, Taute, Holmes (Forsyth 19); Ford, B Youngs (White 68); Genge (Gigena 68), T Youngs (c) (Kerr 48), Cole (Leatigaga 68); Lavanini, Green; Wells, Thompson, Kalamafoni (Coghlan 58).
Referee: Matthew Carley