Northampton returned to the victory trail when they grinded out an 8-3 triumph over Exeter at Franklin's Gardens on Friday.
The defeat was a costly one for the Chiefs as it meant they missed the chance to go top of the Aviva Premiership.
The Chiefs, who went into the match as the league's highest scorers, failed to create many chances against a stubborn Saints side who bounced back from their Boxing Day defeat to London Irish.
The visitors lacked the quality they had shown so far throughout the campaign, allowing a well-oiled Northampton to take victory in front of a record-breaking capacity crowd at Franklin's Gardens.
Gareth Steenson's late penalty was enough, however, to take home a losing bonus point.
The opening exchanges were plagued by injuries as Chiefs' lock Mitch Lees twice received attention from the side-lines, while the home side's Victor Matfield left the pitch with a bloodied nose.
Saints had the best of the early possession, but were often undone by poor handling in advanced areas, before Mike Haywood broke Exeter's stronghold from the line-out. JJ Hanrahan was unlucky not to add to the lead, with his conversion hitting the post.
The visitors did not look like a team capable of going top of the league, and Northampton took advantage when Exeter's chasers strayed offside, giving away a penalty. Hanrahan added three points to the total from close range.
Tom Collins' first half performance was one of the primary reasons behind Jim Mallinder's side's 8-0 lead at the break.
Unlike the first half, the second period got off to a storming start, with the home side winning a penalty inside the first minute. Hanrahan went close from 45 metres out, but his effort ultimately went wide of the target.
With the score unmoved since the half hour mark, Exeter made a plethora of changes, most noticeably replacing Michele Campagnaro with James Short as the entire front row shuffled.
Those replacements had the ideal effect, with Elvis Taione and Ben White combining to win a penalty, which Steenson duly dispatched to hand Exeter a route back into the game.
It was too little, too late, however, as Saints held out for a well-deserved victory in front of the record attendance.
Northampton: 15 Ben Foden (c), 14 Tom Collins, 13 George Pisi, 12 Luther Burrell, 11 George North, 10 JJ Hanrahan, 9 Kahn Fotuali'i, 8 Sam Dickinson, 7 Teimana Harrison, 6 Jamie Gibson, 5 Victor Matfield, 4 Courtney Lawes, 3 Paul Hill, 2 Mikey Haywood, 1 Alex Waller.
Replacements: 16 Dylan Hartley, 17 Ethan Waller, 18 Gareth Denman, 19 Christian Day, 20 Michael Paterson, 21 Lee Dickson, 22 Stephen Myler, 23 Harry Mallinder.
Exeter: 15 Phil Dollman, 14 Jack Nowell, 13 Michele Campagnaro, 12 Ian Whitten, 11 Olly Woodburn, 10 Gareth Steenson, 9 Will Chudley, 8 Thomas Waldrom, 7 Tom Johnson, 6 Don Armand, 5 Geoff Parling, 4 Mitch Lees, 3 Tomas Francis, 2 Jack Yeandle (c), 1 Ben Moon.
Replacements: 16 Elvis Taione, 17 Carl Rimmer, 18 Moray Low, 19 Ollie Atkins, 20 Ben White, 21 Dave Lewis, 22 Will Hooley, 23 James Short.
Referee: JP Doyle