Jeremy Ngakia's sublime second-half strike gave Watford victory at Championship play-off rivals Bristol City, who they leapfrogged in the table up to seventh.
Luca Kjerrumgaard lifted the ball over Robins keeper Radek Vitek to put Watford 1-0 up after just seven minutes, while Saba Goglichidze also hit the post during the first half for the Hornets.
But Scott Twine headed Bristol City level before the break, nodding in a lovely Adam Randell cross, and a point apiece looked to be on the cards.
That was until Ngakia's shot from outside the box curled perfectly into the top corner, allowing Watford to close the gap to sixth-placed Wrexham to three points before the rest of the weekend's games.
Bristol City, meanwhile, drop a place to ninth in the table as they failed to win for a third home game in a row.
The Robins eased to a 5-1 win when these two sides met here in the FA Cup last month but their defence has taken a major hit in the past week with Rob Atkinson following Rob Dickie in being ruled out long-term - and Kjerrumgaard quickly found an early way through their reshuffled rearguard.
Giorgi Chakvetadze shook off Mark Sykes down the wing and picked out Edo Kayembe in the box - he passed straight to the Dane who scooped the ball up and over Vitek at the near post.
Bristol City immediately searched for an equaliser and Ross McCrorie's first-time volley forced a save out of Egil Selvik, while Jason Knight's calls for a penalty for handball were denied.
But Watford almost doubled their lead when Neto Borges brought down Nestory Irankunda and Goglichidze's header from the resulting free-kick hit the post, with a grateful Vitek pouncing on the loose ball.
It continued to be a lively first half as Tomi Horvat's shot from distance required a diving save from Selvik, while at the other end Irankunda almost made it 2-0 with a superb strike from range that curled just wide of the top corner.
But Bristol City levelled 10 minutes before the break as Twine - usually a direct free-kick expert - somewhat uncharacteristically nodded in Randell's cross.