A late fightback from Northampton could not deny Bath a deserved opening day victory at a drenched Franklin's Gardens.
George Ford kicked all Bath's points as the visitors controlled a dreary game with no try-scoring chances until, with six minutes to go, replacement scrum-half Nic Groom scored two tries in four minutes.
Bath held on for the final two minutes to record a victory that will put last season's woes behind them and give new director of rugby Todd Blackadder a winning start.
Northampton gave a first start to big-money signing Louis Picamoles, the French international joining from Toulouse in the summer, while director of rugby Jim Mallinder decided to put son Harry at fly-half, leaving regular number 10 Stephen Myler on the bench.
Bath had a new number eight of their own in British Lion Taulupe Faletau, but the Welsh international lasted just 12 minutes, limping off on the same leg that had a thigh already heavily strapped.
After missing out on the play-offs last season Saints were hoping Mallinder would ignite a backline that failed to fire last term, but in the rain it did not materialise. And the one constant that has been Northampton's lineout was badly disrupted by Bath, who also took the honours in the scrum.
The early pressure from the home side brought two penalties, with both kicked to the corner, but both times England captain Dylan Hartley failed to find his jumper, with David Denton proving a nuisance.
Mallinder missed the first shot at the posts on 23 minutes and instead Ford put the visitors 3-0 in front seven minutes before half-time and five minutes later he added to it with a drop-goal right in front after Saints lost another lineout on their 22.
Mallinder sliced a penalty right in front of the posts wide leaving the home side scoreless and 6-0 down at the break.
And he started the second half with a bad pass that saw Ahsee Tuala knock-on. Bath won a penalty at the scrum just outside the 22 and Ford made it 9-0.
Suddenly Bath were playing full of confidence, Saints were missing tackles and Semesa Rokoduguni was about to touch down after totally flummoxing Tuala with a sidestep, but he was brought back for a forward pass.
As the game entered the last quarter Myler came on at fly-half with Mallinder moving to inside centre position, but the errors were still giving Bath chances and another Ford drop-goal made it 12-0.
The Saints scrum was also in trouble, shoved off their own ball to give Ford an easy three points from 20 metres out.
The TMO decided on another penalty, as Courtney Lawes was judged to have not used his arms in a tackle and from just outside the Saints 22 Ford made it 18-0.
After Chris Cook was sin-binned with six minutes to go Groom scurried over for a try and four minutes later the home crowd suddenly came alive as he juggled the ball to touch down from close range again.
But it was all too late and Bath ended their 16-year hoodoo at Northampton.