The Saints had lost their previous five Premiership outings and have been riddled with injury problems during the last month. But they were able to include former All Blacks fly-half Carlos Spencer among the starting line-up following his recovery from a hand injury.
Hooker Steve Thompson also returned after suffering a dead leg against Narbonne two weeks ago, while Andy Vilk made his first start for Saints this season at inside centre, Chris Budgen was in at tighthead prop and Ben Lewitt swapped to openside flanker. Grant Seely made his 250th appearance for the club at blindside flanker.
Bristol head coach Richard Hill named the side that beat Leicester 15-3 at the Memorial Stadium on December 27, with Mark Regan making his 150th Premiership appearance.
The home side were on the scoreboard after 90 seconds when wing Brian Lima´s flat pass was intercepted on the halfway line by outside centre Jon Clarke who raced 50 metres to score under the posts with skipper Bruce Reihana adding the extras. But Bristol wasted no time with wing David Lemi pouncing for two tries in a three-minute spell.
He charged down a poor clearance attempt by scrum-half Johnny Howard to score the first, then was on hand to finish a 40-metre break by scrum-half Shaun Perry with a 20-metre dash to the line for the second. Fly-half Jason Strange was off target from out wide with his first conversion attempt but nailed the second.
Reihana put the Saints back in the driving seat with 25-metre penalty kicks midway through the first half but sliced a third from in front of the posts just before the half-hour mark. Bristol brought pressure upon themselves close to their own line as Bernardo Stortoni´s pass to Perry found the England prospect on his backside and the ball loose in front of the posts. Centre Sam Cox collected the ball and fed the Argentinian full-back who cleared the danger.
The home side increased their lead on the stroke of half-time as Bristol were again penalised at the ruck just outside their own 22. Reihana landed his third penalty kick from four attempts to give Northampton a 16-12 lead.
The visitors regained the advantage three minutes into the second half from a catch and drive with tighthead prop Darren Crompton claiming the touchdown, and Strange added the touchline conversion. Reihana saw a 45-metre penalty drift past the right upright.
Spencer slotted a 25-metre drop goal between the posts to level the scores before Strange and Reihana missed penalty attempts. Going in to the final 10 minutes, Strange found his mark to put Bristol in front, rather than opting for a possible try-scoring bonus point from a catch-and-drive move.
Bristol were then reduced to 14 men when Dan Ward-Smith was sent to the sin-bin for a high tackle on John Rudd. Northampton capitalised with tighthead prop Chris Budgen scoring the home side´s second try from a series of drives, and Reihana added the extras.
Bristol were then forced to defend their line with Reihana adding a fourth penalty from in front of the posts.