Myles Peart-Harris scored his first Swansea goal in his 11th appearance for the club
Swansea City moved to within two points of the Championship play-off places as Myles Peart-Harris' first goal for the club proved enough to see off Watford.
Peart-Harris slid home from close range to give Swansea a deserved lead at the end of a first half which they dominated.
Watford turned the game into more of a contest after the break, asking questions of Luke Williams' rearguard without ever creating a clear-cut chance to level.
Having gone six games without a victory before their weekend triumph at Oxford United, Swansea are celebrating back-to-back league wins for only the second time this season.
But there was frustration for Tom Cleverley as Watford suffered a sixth away league loss of the season.
The Hornets stay fifth despite failing to build on last Saturday’s second-half demolition of Sheffield Wednesday, while Swansea are 10th.
Having ended a 563-minute Championship goal drought in their win at Oxford United, Swansea began their quest for a first home goal since late September with energy and urgency.
They were sharp both in and out of possession from the outset, with Peart-Harris having three sights of goal – and seeing a penalty claim turned down - before the opener came.
One early Peart-Harris effort left Daniel Bachmann scrambling to save at the foot of the post, before Ben Cabango thought he had scored from a well-worked corner only for the offside flag to save Watford.
Swansea's first-half superiority was eventually rewarded when Josh Key fed Goncalo Franco and his deep cross was headed back across the face of goal by Ronald.
With Watford's rearguard nowhere to be seen, Peart-Harris turned in his first goal since arriving on loan from Brentford in the summer.
Watford are unbeaten at home in the Championship this season, but have lost six of their eight away league games
Franco wasted a chance to extend Swansea's lead early in the second half, the Portuguese midfielder slicing off target when more composure was required, before Ronald's 40-yard effort drifted narrowly over the top.
Watford are among the Championship's top scorers this season, yet it was not until midway through the second half that they began to show any threat.
Ryan Andrews unleashed a fierce drive which was blocked by Harry Darling, before the Swansea centre-back produced a fine challenge on Kawdwo Baah as he drove into the box.
Watford enjoyed their most dangerous spell in the closing stages, with Giorgi Chakvetadze finding space on the edge of the box but lifting his effort over the bar before Festy Ebosele blasted wide in stoppage time.
Swansea head coach Luke Williams:
"I am pleased that we played well again. I think it's fair for me to say that the players deserved to win.
"I think in the first hour, they were the only team that looked like they were going to go and win the game.
"In the last half hour Watford applied a lot more pressure to us and we coped with that pretty well, so I am pleased.
"The players carried on from the previous performance. Really I think we have been close to that type of performance - I don't think it was that different to Millwall - but it feels different if you don’t win."
Watford head coach Tom Cleverley:
"It's two steps forward and one step back - that's the story of our season. If you do that your trajectory will be in an upwards way, and it is, but we could be so much better.
"We keep taking that one step back. We have a game again in three days when we can put this right, but it's disappointing.
"I will hold my hands up. We paid Swansea too much respect in possession. We had no identity at all for the first hour.
"It's a disappointing goal to concede but I can't have any complaints about the result."
