Swansea's slide towards relegation continued on Saturday as Etienne Capoue's first-half goal sealed a narrow 1-0 win for Watford in an error-strewn encounter at Vicarage Road.
In a low tempo first-half, Watford dominated the early stages and went closest just before the half hour when Lukasz Fabianski tipped Troy Deeney's clip over the bar as the Swans were forced under the cosh.
The visitors were undeterred though and continued to press, though they were pegged back minutes before half-time when Capoue robbed Alfie Mawson, before volleying past Fabianski at the second attempt.
Walter Mazzarri's Hornets seemed content to grind out the result in the second half and despite a host of attacking-minded changes from Paul Clement, they did just that.
Heurelho Gomes was seldom troubled in the Watford goal and the result does little for Swansea, who remain firmly embroiled in a relegation tussle, two points from safety heading into the final five fixtures of the season.
Paul Clement was left without skipper Jack Cork after he sustained an ankle injury against West Ham last weekend; the midfielder's absence one of four Swansea changes.
The return of Hornets' top-scorer Troy Deeney was one of three tweaks to the starting eleven by Mazzarri; the striker was left on the bench for their 4-0 defeat to Tottenham, though reports suggesting a rift between the pair were swiftly refuted by the Italian.
Though Watford imposed themselves with much of the early possession, neither side could spark the game into life, until Gylfi Sigurdsson forced a point-blank save out of Gomes under pressure from Capoue nine minutes in.
Iceland international Sigurdsson soon had another long-range effort held by Gomes, but Swansea's efforts amounted to half-chances and it was Watford, all-but guaranteed Premier League survivors, who went closest just before the half hour; Fabianski leaping like a salmon to keep out Deeney's connection on Janmaat's cross.
The spike in action was short-lived though and it was the Swans who continued to press, but with three minutes left in the half, they were architects of their own downfall when Mawson gifted Watford the opener.
Capoue stole the ball from the young defender's feet and - though his first shot was saved - made no mistake the second time around as he volleyed past Fabianski via the post.
As had panned out in the first half, the second half began in a sluggish fashion. Sigurdsson went close on 50 minutes when he dropped his shoulder and lost Sebastian Prodl, but his curling effort dropped disappointingly wide.
Ki Sung-Yeung floated a cross over the bar in a commanding position following a rare flowing passage of play from the visitors, but as the game progressed it transpired that Mazzarri had instructed his men to grind out the narrow win.
Given the looming threat of relegation, Clement's men showed little sign of the fighting spirit one would expect; at times they seemed to sense the chance of an equaliser though nothing came to fruition.
At the death, skipper for the day Sigurdsson had two chances to earn a precious point for his side, but as he advanced towards the box at the second attempt and beat Adrian Mariappa, Abdoulaye Doucoure intervened with a vital touch to remove the ball from his possession and ensure the three points remained in Hertfordshire.
Watford: Gomes (7), Janmaat (7), Prodl (6), Mariappa (6), Holebas (7), Capoue (6), Doucoure (7), Cleverley (6), Amrabat (6), Deeney (6), Niang (6)
Subs used: Okaka (5), Kabasele (5), Behrami (4)
Swansea: Fabianski (7), Naughton (6), Fernandez (7), Mawson (5), Olsson (6), Fer (5), Ki (5), Fulton (6), Narsingh (5), Llorente (5), Sigurdsson (7)
Subs used: Carroll (6), Borja (5), Ayew (5)
Man of the match: Abdoulaye Doucoure