Saracens slumped to their heaviest defeat in four-and-a-half years after England full-back Ben Foden helped Northampton overwhelm their Aviva Premiership title rivals.
Foden crossed twice to improve his chances of winning a place on the bench against Australia at Twickenham next Saturday as Saints romped to a 41-20 victory at Franklin's Gardens.
Luther Burrell, who was released by England last week, asked questions of Saracens' defence throughout and deserved his 64th-minute try, even if it did involve a forward pass.
The rout was completed by Jamie Elliott, Ken Pisi and man-of-the-match Samu Manoa, the marauding American lock whose early ball-carrying was instrumental in Saints cruising into an early 17-3 lead that was never challenged.
Fly-half Stephen Myler kicked a penalty and four conversions in a memorable afternoon for Northampton.
Exeter Chiefs ran in six tries to take maximum points and move up to fifth place in the Aviva Premiership table and leave Worcester Warriors still looking for their first win of the season.
Tries from flanker Ben White and captain Dean Mumm, both converted by fly-half Gareth Steenson, in the opening 10 minutes for Exeter helped the Chiefs to a 14-6 half-time lead, Warriors fly-half Ignacio Mieres kicking two penalties.
Exeter showed real resolve in the second half with a second try from White plus one each from full-back Phil Dollman, lock Damian Welch and replacement scrum-half Haydn Thomas. Steenson converted two and his replacement Henry Slade one in the 40-6 victory.
Harlequins stopped their four-match losing run with a comfortable 24-3 win over Sale at the Stoop to allow them to leapfrog their opponents into sixth place.
The first half was dour with the only scores coming from penalty kicks, three from Ben Botica to one from Danny Cipriani giving the hosts a 9-3 interval lead.
Sale rallied briefly after the restart but a superb team try finished off by Luke Wallace and a further penalty from Botica set the Quins on the road to victory. A late converted try from replacement Jack Clifford rewarded Quins' second-half dominance.