Saracens remain unbeaten at home this season after Maro Itoje’s late show undid a fine defensive performance from Bath Rugby.
Rhys Priestland had scored two penalties and converted an early Tom Homer try at the break, but the hosts proceeded to chip away at their 13-point lead after the interval.
Charlie Hodgson struck twice from the tee before coming up inches short of crossing the whitewash, but ferocious Bath defence was eventually undone by Itoje.
The 21-year-old lock, sent back to Saracens by England coach Eddie Jones last week, powered deep into Bath territory before Schalk Brits crossed and Hodgson converted to level the scores.
Former England fly-half Hodgson struck a further two penalties, the first after smart work from Itoje at the breakdown, condemning Bath to a sixth league defeat in nine games.
But it had taken Saracens' biggest ever comeback in Aviva Premiership Rugby, after scoring 19 unanswered points.
Bath were lively from the off as Matt Banahan, starting at centre, burst through the Saracens midfield only to throw a wayward pass to Semesa Rokoduguni, who was ushered into touch by Richard Wigglesworth.
It looked as though Bath had gone over from the resulting lineout drive, but they had to settle for a penalty which Priestland knocked over.
Saracens nearly responded in the eighth minute as Duncan Taylor went over in the corner, but he was called back for a forward pass in the build-up by referee Dean Richards.
And it was Bath who crossed the whitewash first as, five minutes later, Homer picked an excellent line off debutant Dan Bowden after Bath’s forwards asserted themselves from a lineout.
Priestland added the extras and Bath, somehow, made sure Saracens remained pointless at half-time.
First Max Lahiff – an injury replacement for Nick Auterac – and Henry Thomas got the upperhand at the scrum after relentless Saracens pressure and won the penalty.
And though Saracens weren’t lacking for visits to Bath’s 22, uncharacteristic handling errors continued to spoil their efforts.
Before the half was out Priestland extended the lead out to 13-0 – soon after the Wales fly-half missed a touchline effort in blustery conditions – when Bath found more joy in the maul.
Saracens started the second-half with far greater purpose and though Hodgson missed one penalty, he made up for it by nailing two inside the first ten minutes.
Priestland then missed a very kickable penalty from 35 metres out soon after, and balance was restored at scrumtime with the introduction of USA prop Titi Lamositele.
Pressure was building – Homer made a crucial interception to keep the Premiership champions out before Leroy Houston held up Hodgson just short of the line.
But Itoje eventually broke Bath open after bursting down the right flank and when Saracens recycled the ball, Brits surged through a gap and had just enough reach to dot down.
Hodgson added the extras two minutes to go and he nudged Saracens ahead after Itoje made a menace of himself in the ruck. A further Hodgson penalty sealed the victory.