Troy Deeney scored the only goal of the game with a rasping finish to move Watford six points clear of the Premier League relegation zone with 1-0 win over Everton.
No team has conceded more top-flight goals at home than the 26 Watford have shipped, and when Oumar Niasse inadvertently hit the woodwork in the first half, the home crowd would have been forgiven for expecting another difficult examination for their defence.
But, in a game in which opportunities were extremely limited, Deeney took his with aplomb 11 minutes from time to light up an otherwise disappointing spectacle.
AS IT HAPPENED: Watford v Everton
Jordan Pickford had previously produced a fine save to deny Kiko Femenia, who had seen the Everton goalkeeper's clearance deflect off Deeney and into his path.
However, he could do little to stop the Watford captain from settling the contest as the forward rifled a stunning finish into the top-right corner.
Sam Allardyce's visitors had no response as Javi Gracia claimed his second win as Watford manager, moving them on to 33 points and into the top 10, just one point and one place behind Everton.
Key Opta Stats:
Watford kept a clean sheet at Vicarage Road for the first time in their last eight top-flight games.
Everton have registered just one win in their last 22 Premier League away games (D9 L12), losing each of the last four.
Watford enjoyed only their third win over Everton in their last 25 meetings in all competitions (D3 L19).
After picking up 10 points in his first four Premier League games as Everton boss, Sam Allardyce has seen his side accrue just nine in the last 10.
Watford had to wait until the 55thminute to register their first shot on target of the game, via a Troy Deeney effort (there had only been one before that from Everton).
Deeney scored from open play for the first time in his last 27 Premier League games (v West Brom April 2017).