The Hammers got back to winning ways thanks to this formidable festive victory at Vicarage Road, where they simply stung the hapless Hornets with a ruthless attacking display

Although Emmanuel Dennis put the hosts ahead inside the opening five minutes that was as good as it got for wobbling Watford, who were simply overwhelmed by West Ham United’s intent, incisiveness and invention.

Tomáš Souček levelled as the half-hour mark approached before Saïd Benrahma put David Moyes men in the driving seat a couple of minutes later.

And with the Hammers then controlling the second period, Mark Noble’s penalty on the hour took him onto 47 Premier League goals – making joint-second in the Club’s all-time scoring charts alongside Paolo Di Canio (47) and only behind Michail Antonio (53) – before Nikola Vlašic recorded his first strike in Claret & Blue in stoppage-time.

A Boxing Day defeat to Southampton had extended West Ham’s win-less run to five matches in all competitions and, following that loss, Moyes made a quartet of changes as skipper Noble – replacing the suspended Declan Rice – Antonio, Ben Johnson and Manuel Lanzini returned to the starting line-up, while Vlašić, Arthur Masuaku and Pablo Fornals each dropped to the bench.

Constrained by COVID-19, Watford’s last match had been a 2-1 victory at Brentford 18 days ago and, having seen three fixtures subsequently postponed by the pandemic, the Hornets had kicked off in 17th-spot, eleven places and 15 points behind West Ham.

But just as the Saints' fresh legs had seen them take an early lead at London Stadium 48 hours earlier, then the Hornets equally succeeded in quickly breaking the deadlock.

Indeed, there were only four minutes on the clock, when Dennis collected from Joshua King on the edge of the area and, after patiently waiting to explore his options, the Nigerian international then took a couple of strides forward before whipping an 18-yarder around the unbalanced Craig Dawson, beyond the groping glove of Łukasz Fabianski and under the right-hand angle.

With his side having finally returned to action, Claudio Ranieri had made a trio of changes with Adam Masina, Francisco Sierralta and Ozan Tufan each returning in place of former Hammer Jeremy Ngakia, Tom Cleverley plus William Troost-Ekong and the Italian could not have asked for a better start after that long absence.

But having gone behind all too early for a second successive match, West Ham quickly dusted themselves down and, after Jarrod Bowen weakly scuffed into the clutches of Daniel Bachmann, Benrahma gave a better indication of what was to come with a rising 20-yarder that scorched through the Hertfordshire haze on its way to rocking the Watford crossbar.

Apart from picking that Dennis opener out of his net, Fabiański had subsequently been a virtual spectator as West Ham continued to stoke the Hornets’ nest and, with the half-hour mark approaching, Moyes boys turned the game on its head with two quick-fire goals.

On 27 minutes, the Hammers worked their way down the right flank, where Vladimír Coufal played the ball inside to Bowen, who threaded the perfect pass to Souček and the Czech Republic international gleefully drilled a low 15-yarder inside the base of the flat-footed Bachmann’s left-hand upright to level with his third goal of the season.

Within 60 seconds or so, West Ham went one better, taking the lead with a raid down the opposite touchline, where Lanzini won possession before releasing Antonio, whose inch-perfect cut-back enabled Benrahma to take his tally to eight for the campaign with a sliding 10-yarder.

‘Barcelona we’re coming for you!’ chanted the Hammers fans, who having just seen their team overturn that early deficit to secure an interval lead, now turned their thoughts to next year’s potential Europa League opponents.

Having been forced to replace the injured Kiko Femenía with Imran Louza just before the break, Ranieri also introduced João Pedro at the expense of Cucho Hernández for the restart and the Hornets’ head coach’s second-half plans soon looked to have gone up in smoke when the on-fire Hammers scorched their way into the Watford goalmouth, where Bowen volleyed home.

But after being directed to his monitor by Video Assistant Referee Martin Atkinson, on-pitch official Darren England ruled out the effort for a foul by Souček on Dennis in the build-up and, buoyed by that let-off, the hosts broke deep into West Ham territory, where Moussa Sissoko unleashed a sizzling 20-yarder that the flying Fabiański expertly diverted to safety.

That VAR screen may have rescued Watford once but, on 58 minutes, there was no reprieve for the hosts second time around when referee England made another visit to his pitch-side monitor and adjudged Bachmann to have bundled over Man-of-the-Match Bowen as ‘keeper and attacker went in pursuit of Masina’s chest down in the six-yard box.

Cool as you like, Noble fired the consequent penalty into the bottom left-hand corner – his 28th successful Premier League penalty and a figure only surpassed by former Hammer Frank Lampard (32) and Steven Gerrard (29) - as the embarrassed Bachmann headed in the opposite direction.

In reply, King threatened on a couple of occasions during an, at times, niggly finale that saw both physios attend the scene, former Hornet Dawson booked for time-wasting and Masuaku, Vlašić and Alex Král each replace Johnson, Benrahma and Lanzini.

Pressing until the final whistle, Antonio might even got on the scoresheet but Bachmann brilliantly blocked his point-blank shot before West Ham did, indeed, get that festive fourth goal in stoppage-time when the barnstorming Bowen burst into the box and cut-back to the unmarked Vlašić, who cemented victory with a comfortable tap-in to finally break his Hammers duck on his 16th outing for the Club.

Watford: Bachmann, Femenía (Louza 40). Masina, Cathcart, Sierralta, Sissoko, Tufan (Sema 62), Kucka, King, Hernández (Pedro 46), Dennis. Unused subs: Angelini, Gosling, Fletcher, Morris, Conteh.

West Ham: Fabianski, Coufal, Johnson, (Masuaku 81), Diop, Dawson, Souček, Noble, Lanzini (Král 89), Benrahma (Vlašić 85), Bowen, Antonio. Unused subs: Areola, Yarmolenko, Fredericks, Oko-Flex, Alese, Ashby.

Booked: Dawson (80).

Referee: Darren England.