Bath gave their new millionaire owner Bruce Craig a second Guinness Premiership victory in three days as they edged closer to the title play-offs with a thrilling 21-20 win over Northampton.
Tries in each half by England internationals Lee Mears and Matt Banahan underpinned Bath's tense success, putting them just two points behind fourth-placed Wasps, who they meet at Twickenham on Saturday.
Centre Olly Barkley added 11 points from the boot to quell a much-changed Saints side, although Northampton stayed in touch through five Shane Geraghty penalties and a Paul Diggin try.
Bath, relegation candidates before Christmas, have now lost just one of their last 10 league games.
It was a close call though, with Barkley's winning kick arriving six minutes from time after Northampton flanker Neil Best was sin-binned.
The only consolation for Saints was a losing bonus point that left them just behind Premiership leaders Leicester, and victory over Saracens on Saturday will guarantee a home semi-final.
The closing seconds provided a frantic climax as Saints threw everything at their opponents, yet Bath kept their composure when it mattered to secure another vital victory.
Northampton made 12 switches ahead of that Franklin's Gardens clash.
Only centre Jon Clarke, wing Bruce Reihana and lock Ignacio Fernandez Lobbe remained following a 38-23 victory over Gloucester weekend, but Bath went with 10 of the side that brushed aside Sale Sharks.
One of Bath's switches was at fly-half though, where an ankle injury sidelined the influential Butch James and meant a rare recent first team start for Nicky Little.
Barkley and Geraghty exchanged penalties inside the opening seven minutes as both sides sparred for territory, but Bath then saw Little sin-binned following a reckless high tackle on Diggin.
Referee J P Doyle had no option other than to show the Fijian a yellow card. Geraghty though, botched a simple penalty chance as Little trudged off, sending his kick wide.
It was a let-off for Bath, yet they were punished nine minutes later with Little waiting to return as Northampton went through the phases and created a well-worked try for Diggin.
Although Geraghty missed the touchline conversion attempt, Bath had been served notice - a dozen changes or not - that Saints meant business.
It was a ferociously-intense contest, with scoring opportunities at a premium, but Barkley cut the deficit through his second penalty after Geraghty high-tackled home full-back Nick Abendanon.
Barkley missed a more straightforward penalty attempt four minutes later, and as hard as they tried, Bath could not find a way through Northampton's defence.
That was until Saints offered them some assistance by mentally switching off on the stroke of half-time.
Hooker Brett Sharman overthrew a lineout that almost led to a Bath score, and when he repeated his inaccuracy barely 60 seconds later, Saints suffered on the scoreboard.
Flanker Julian Salvi pilfered possession from Northampton lock James Cannon, and Mears was driven over by his fellow forwards to give Bath an 11-8 interval advantage.
A Geraghty penalty brought Saints level early in the second period, but Bath began to assert dominance up front, notably at scrum time.
They were awarded two penalties and a free-kick in quick succession, yet Saints somehow absorbed pressure from six consecutive scrums and cleared the danger.
Northampton boss Jim Mallinder had seen enough of the scrum troubles though, and he sent on international props Soane Tonga'uiha and Euan Murray in an attempt to keep Bath at bay.
But before either player could get their boots dirty, Bath struck courtesy of a simple close-range move than ended with Banahan powering over.
Barkley added the extras, only for two more Geraghty penalties during a four-minute spell to revive the possibility of an away win.
Geraghty's fifth successful strike then inched Saints ahead, and with the rampaging Tonga'uiha making his presence felt in open play, Northampton were revitalised.
But Best then collected a yellow card, Barkley slotted the resulting penalty and 14-man Saints could not climb back off the canvas as Geraghty rifled a drop-goal attempt agonisingly wide.
Tries: Mears, Banahan
Pens: Barkley 3
Pens: Geraghty 5
Bath: 15 Nick Abendanon, 14 Joe Maddock, 13 Shontayne Hape, 12 Olly Barkley, 11 Michael Stephenson, 10 Nicky Little, 9 Michael Claassens (c), 8 Luke Watson, 7 Julian Salvi, 6 Ben Skirving, 5 Stuart Hooper, 4 Danny Grewcock, 3 David Wilson, 2 Lee Mears, 1 David Barnes.
Replacements: 16 Pieter Dixon, 17 Nathan Catt, 18 Aaron Jarvis, 19 Scott Hobson, 20 Daniel Browne, 21 Scott Bemand, 22 Tom Cheeseman, 23 Matt Banahan.
Northampton: 15 Barry Everitt, 14 Paul Diggin, 13 Joe Ansbro, 12 Jon Clarke, 11 Bruce Reihana, 10 Shane Geraghty, 9 Alan Dickens, 8 Mark Hopley, 7 Neil Best, 6 Mark Easter, 5 James Cannon, 4 Ignacio Fernandez Lobbe (c), 3 Brian Mujati, 2 Brett Sharman, 1 Regardt Dreyer.
Replacements: 16 Andy Long, 17 Euan Murray, 18 Soane Tonga'uiha, 19 Juandre Kruger, 20 Roger Wilson, 21 Lee Dickson, 22 James Downey, 23 Grant Pointer.
Referee: JP Doyle