Ryan Shawcross and Peter Crouch scored either side of the interval to earn Stoke a first win in six and pile more misery on Walter Mazzarri's Watford.
Potters skipper Shawcross, whose last goal came exactly two years and two days earlier, fired past an unconvincing Heurelho Gomes in half-time stoppage time before Crouch benefited from some abject defending from Sebastian Prodl for his 98th Premier League goal shortly after the resumption.
The 2-0 success lifted Mark Hughes' men up to 11th in the table, above the injury-ravaged Hornets, whose head coach Mazzarri looks under increasing pressure amid fears they could be in the midst of a similar collapse to the one they suffered in the second half of last season.
Having finished the calendar year shipping 68 top-flight goals, Potters boss Hughes may have been feeling the heat too, and he sacrificed flair by leaving Xherdan Shaqiri, Giannelli Imbula, Ibrahim Afellay and Bojan Krkic among his substitutes, instead entrusting the old guard of Charlie Adam, Jonathan Walters and Crouch.
The Welshman persisted with his three-man defence, though, having switched to it for November's win at Vicarage Road and at least had Marko Arnautovic back from a ban to try to unlock the visitors.
It was he who was set free by Joe Allen's through ball after a mistake by Prodl and the Austrian cut the ball across the six-yard box for Walters, who might have scored were it not for Miguel Britos' brilliant intervention.
That had been one of the few occasions the Potters played their way through the Watford defence, although Gomes was fortunate Walters could not capitalise when he pushed Crouch's header into Valon Behrami.
Watford were finding it equally difficult to conjure up chances as promising attacks broke down when Troy Deeney lost support and Allen stole in to rob Adlene Guedioura.
A half between two sides who had conceded a combined eight goals at the weekend was heading for a scoreless conclusion before Shawcross struck in stoppage time.
The Stoke skipper had stepped away from Guedioura to meet Adam's corner 12 yards out and Shawcross' effort was only helped into the corner by Gomes, with no man on his near post to spare his stopper's blushes.
That opener came in the fourth minute of stoppage time and four minutes after the interval Stoke had doubled their lead.
The Hornets had nearly levelled when Abdoulaye Doucoure's fierce right-footed try was pushed out by Lee Grant before their defensive shortcomings once again reared their head.
A semi-cleared corner found its way back out to Adam on the left and his weak low cross somehow managed to get past Prodl, with Crouch, standing behind him, knowing little about the finishing touch which saw the ball divert off his thigh and into the corner.
It was the first time since February 2015 that the 35-year-old had netted in back-to-back Premier League games and took him to 98 career efforts in the division.
Against a team bereft of confidence and fit senior players, the result already looked assured, though Walters was twice denied a third by Gomes and Shawcross stabbed wide.
The Hornets were unable to find a way back, though Jerome Sinclair and Prodl came close with headers, and a sixth defeat in eight will do little to help the job security of Mazzarri.