Christmas came early on Wearside as Patrick van Aanholt’s second-half strike delivered three points against Watford.
The Hornets wasted countless opportunities in the opening period as Nordin Amrabat and Miguel Britos went closest, but the Black Cats bided their time and following the restart they made the visitors pay.
A touch of class from Adnan Januzaj set the gears in motion as he left his man for dead before picking out Jermain Defoe, with the striker flashing the ball back into the danger zone where van Aanholt crashed it in via the post.
Sunderland could have added to their lead although Walter Mazzarri’s side did rally late on to set up a grandstand finale, but the Black Cats held firm and returned to winning ways to move within a point of safety.
Sunderland made three changes at the Stadium of Light – two of which were enforced – as Donald Love, Didier Ndong and Victor Anichebe were named in the starting XI.
Billy Jones and Jan Kirchhoff missed out due to injury as captain John O’Shea dropped to the bench, with the Black Cats reverting to four at the back as Januzaj, Fabio Borini, Defoe and Anichebe formed a fearsome front quartet.
Former Black Cat Younes Kaboul started for the Hornets and he was forced into an early error as pressure from Defoe saw the Frenchman concede a corner in the opening 20 seconds.
It was taken quickly and, at the second attempt, Defoe managed to pick out Jason Denayer whose header looped into the grateful arms of Heurelho Gomes.
Within a minute the stopper’s opposite number, Jordan Pickford, was called into action, with Amrabat forcing the ‘keeper into a flying save after a well-worked corner saw the midfielder volley at goal from the edge of the box.
Both sides continued to see the ball in a lively opening 15 minutes, but it was the visitors who continued to create clear-cut opportunities as Troy Deeney sprung the offside trap before failing to find Odion Ighalo.
And Ighalo went close again soon after, as an Ndong error allowed Jose Holebas to fire a ball into the near post where the striker diverted it across the face of goal.
Watford continued to turn the screw and with 27 minutes played they should have taken the lead, but somehow Britos headed off target – and against Kaboul - from four yards after the Hornets queued up at the back post.
Content to counter, Sunderland’s best opportunity of the opening period fell to Anichebe who powered down the flank and left Amrabat trailing in his wake, only to see his effort blocked.
Moments before the Nigerian’s effort Sebastian Prodl headed straight at Pickford and the defender injured himself in the process, with Christian Kabasele called on as his replacement.
Deeney also appeared a little shaken as the first-half came to a close, but despite hobbling about he was patched up at the break and emerged for the second period, as Sunderland looked to build on a strong end to the opening period which saw van Aanholt denied.
And the Dutchman’s chance was a sign of things to come as he opened the scoring with 50 minutes played.
Januzaj fashioned the chance with a stunning shimmy before feeding Defoe who was forced wide, but the 34-year-old showed brilliant awareness to play the ball back into the danger area where Watford failed to clear and van Aanholt pounced.
It could have been 2-0 on 62 minutes as Sunderland continued to crank up the pressure, with Anichebe’s first-time effort wrong-footing Gomes who stood motionless as the striker’s effort whistled past the post.
Kaboul received a warm ovation from the red and white army prior to kick-off and he showed why shortly after, thwarting Lamine Kone who looked to power the Black Cats into a commanding lead.
But the Black Cats remained menacing on the front foot, and largely untroubled at the back, as Januzaj continued to weave his magic in the no.10 role.
Nervy moments followed as the game moved into the final ten minutes as Isaac Success teased the Sunderland backline, but Love, who produced a standout performance at right-back, refused to be beaten.
And even when the tricky winger did manage to get past the youngster, Papy Djilobodji came up trumps to slide in and clear the danger as the Hornets searched for a late equaliser.
Pickford was forced into action on multiple occasions as the visitors continued to pepper the Black Cats backline, but like his team-mates he pulled out all the stops to ensure three points were secured as Christmas arrived early at the Stadium of Light.
Next stop, Old Trafford.
Sunderland: Pickford, Love (Larsson 87), Djilobodji, Kone, van Aanholt, Ndong, Denayer, Anichebe, Borini (Khazri 90), Januzaj (O’Shea 77), Defoe.
Substitutes: Mannone, Asoro, E Robson, Honeyman.
Watford: Gomes, Britos, Kaboul (Janmaat 76), Prodl (Kabasele 31), Amrabat, Deeney,Behrami, Zuniga (Success 55) , Ighalo, Holebas, Capoue.
Substitutes: Pantilimon, Cathcart, Guedioura, Sinclair, Janmaat.