Odion Ighalo’s 10th goal of the season handed promoted Watford a third successive Barclays Premier League victory and plunged Sunderland deeper into relegation trouble.
The Nigerian’s fourth-minute strike proved enough to clinch all the points in a 1-0 win at a wintry Stadium of Light as the visitors launched an early blitz and then defended their lead with little difficulty to claim their seventh top-flight win of the campaign.
Sam Allardyce’s men at least made a game of it after a dreadful start with substitute Jermain Defoe seeing a strike correctly ruled out for offside and forcing a fine late save from goalkeeper Heurelho Gomes, but the visitors were the better side and were worthy winners.
Allardyce has built his new-look Sunderland team on defensive solidity and the ploy has proved largely successful in recent weeks with a back three having given Black Cats goalkeeper Costel Pantilimon welcome protection.
However, he had to rip his plan up within 19 minutes as Watford tore into Sunderland with relish, with Ighalo, Troy Deeney and Almen Abdi in rampant mood.
The visitors took the lead when full-back Allan Nyom combined with Abdi down the right for the latter to slide the ball in to Ighalo, whose sliding effort might have clipped defender Sebastian Coates as it rolled past the stranded Pantilimon.
Had Billy Jones not been in the right place at the right time five minutes later, Abdi might have made it 2-0 from Nathan Ake’s cross, and his side was desperately fortunate to escape further mishap with 11 minutes on the clock.
Ighalo brilliantly tricked his way past John O’Shea, making his 400th Barclays Premier League appearance, only to see Pantilimon block his initial effort and Coates his follow-up before Abdi’s strike was repelled and Jose Manuel Jurado rattled the post from the rebound.
Fabio Borini could have levelled after running on to Yann M’Vila’s 17th-minute pass, but shot inches wide of the far post.
Allardyce simply had to act and he did so with 19 minutes gone, replacing wing-back DeAndre Yedlin with midfielder Jack Rodwell and switching from 3-5-2 to 4-2-3-1.
The change eventually paid dividends as the Black Cats gradually forced their way into the game, although not before Pantilimon had to palm away Etienne Capoue’s 26th-minute effort.
Borini sent a half-volleyed attempt wide after Gomes had needlessly palmed an M’Vila corner straight to his feet, but the keeper redeemed himself with a good reaction save after M’Vila’s 44th-minute free-kick skidded off defender Miguel Britos’ head and sped towards his own goal.
The home side started the second half in much better fashion than they had the first with defender Craig Cathcart throwing himself into the path of Steven Fletcher’s shot and Gomes parrying another from Rodwell in quick succession.
Duncan Watmore sent a rasping drive just wide with 13 minutes remaining, but Defoe saw an 82nd-minute snap-shot brilliantly saved by Gomes and then failed to make meaningful contact with Patrick van Aanholt’s cross in front of goal two minutes later with Ighalo having passed up three glorious opportunities.