Arriving at Goodison Park Watford were without an away goal since January.

Little surprise then that it took a solitary strike to leave them still searching for Premier League sanctuary.

Ross Barkley provided the moment of inspiration – a curling effort just before the hour – on a night where the Hornets were plucky but ultimately lacking attacking quality.

A fourth defeat on the spin will not sit well with those connected to Vicarage Road and the Hornets remain in the relegation conversation – six points clear with two games to play – ahead of a trip to Stamford Bridge on Monday.

Worse still will be the sense of what could have been, with Troy Deeney missing a fine opportunity shortly before the decisive Everton goal.

Deeney’s return in attack, after being left on the bench for the 3-0 defeat at Leicester City, provided the main talking point before kick-off.

He partnered Stefano Okaka in a front two with Walter Mazzarri, who was shorn of Everton loanee Tom Cleverley in the heart of midfield, opting for a 3-5-2 formation as Valon Behrami returned for his first start since mid-March.

Okaka’s inclusion looked to be a ploy to get more support around Deeney, who has been painfully isolated when involved recently, but it was Okaka who looked liveliest early on when going close from 20 yards.

The hosts had, however, started like a side which has lost just twice at home all season and Barkley drew the very best from Heurelho Gomes with six minutes on the clock.

Picking the ball up on the edge of the box, the Everton number eight skipped beyond a flat-footed Watford defence before curling left-footed towards the bottom left corner, only to be denied by a strong hand from Gomes.

The Brazilian had to be similarly alert as he got down to deny Tom Davies in stunning fashion after the teenager turned Leighton Baines’ corner goalwards.

Watford were by no means making up the numbers in what was proving to be an attritional evening on Merseyside and kept Everton honest in defence, particularly when attacking down their left.

Still a clinical edge, which has been lacking for much of the season, deserted them once more, and Adrian Mariappa’s towering header from Jose Holebas’ clipped cross was their best opening of the first half hour.

Much of the games brighter moments had been provided by Everton’s Davies and a half-time switch to right-back did little to quell the 18-year-old’s influence.

He led a number of forays down his flank as Everton started the second half brightly.

It was the Hornets who should have led eight minutes after the restart, though, when their best piece of play of the night presented Deeney with a golden chance.

Daryl Janmaat, who was a consistent presence at full-back throughout the night, played a pass into Okaka before collecting the forward’s clever return flick.

From there the Dutchman drove into the box and squared for Deeney who could only turn wide under pressure from Ashley Williams from six yards.

It would prove to be a costly error as some poor Watford defending allowed Everton to take the lead moments later.

A loose ball found Barkley in space in the middle of the park and he was allowed the freedom of Goodison to drive at the heart of the Watford defence.

With Sebastian Prodl retreating at pace and turning his back – a cardinal sin for any defender – Barkley needed only pick his spot as he whipped a shot across Gomes into the bottom corner from distance.

The goal only served to increase Ronald Koeman’s side’s control on proceedings and they began to cause Watford issues at regular intervals.

Gomes was lucky not to be punished after spilling a routine shot at the feet of Lukaku and Morgan Schneiderlin went close with a header from a corner.

What Watford did muster in response was of little concern to the Toffees and only Okaka’s volley, which forced a fine stop from Joel Robles, troubled the hosts as they claimed a record 13th home win of the season.

A six-point cushion should be enough to ensure top flight football for a further year, but having reached the 40-point mark in mid-April, the Hornets are making hard work of an apparently simple task.

What is certain is Mazzarri’s men must lift themselves for the visit to Chelsea on Monday as well as their closing day clash with Manchester City next Sunday.

Everton: Robles, Holgate (Valencia HT), Williams, Jagielka (C), Baines, Davies, Schneiderlin, Gueye, Barkley (Kone 85), Mirallas, Lukaku

Subs not used: Hewelt, Barry, Besic, Pennington, Williams

Watford: Gomes, Kabasele (Zuniga 37), Mariappa, Prodl, Holebas, Janmaat, Doucoure, Behrami (Amrabat 72), Capoue (Niang 81), Okaka, Deeney   (C)

Subs not used: Pantilimon, Success, Watson, Eleftheriou