Watford’s winless start to the season was extended to a third game tonight as West Ham United showed why they are strong candidates for an instant return to the Premier League with a 4-0 victory at Vicarage Road.

The Hornets had some cause to feel aggrieved at finding themselves two goals down at the interval, although they were up against it from the third minute when slack defending allowed James Tomkins to head the opener.

However, Watford were promising for much of the first half thereafter and created more of the chances but their inability to capitalise on them was punished in first-half injury-time when Joey O’Brien doubled the visitors’ lead.

West Ham always looked in control after the break and capable of upping their game if they needed to, producing a slick and incisive move midway through the half that gave Carlton Cole the easiest of finishes.

That knocked the stuffing out of the hosts and, after a couple of close calls, they conceded a fourth late on to Scott Parker, raising more concerns about the Hornets’ lack of firepower after they failed to register at home for the second consecutive match.

Despite not picking up three points in the opening two games, Sean Dyche opted to keep faith with the same starting line-up for the third match running.

The Hammers, who got off the mark at Doncaster Rovers on Saturday, had all their big guns on show as Sam Allardyce made just the one change from that 1-0 victory, with Cole replacing Frederic Piquionne.

Watford went straight on the attack from the opening whistle, with a Carl Dickinson throw from the left causing problems in the Hammers box. Martin Taylor managed to recycle the ball back to Dickinson, whose cross was retrieved by Craig Forsyth, he laid it back to John Eustace and the Hornets skipper connected well with a right-footed drive that Robert Green managed to grasp at the second attempt, under pressure from Marvin Sordell.

The action immediately switched to the other end where the visitors won their first free-kick and Matt Taylor struck a fine left-footed effort across goal that Scott Loach did well to get across to and push behind for a corner.

However, Watford’s defending from Matt Taylor’s set-piece from the right was disappointing, with Tomkins allowed to get in largely unchallenged at the back post to head firmly home and give West Ham a third-minute lead.

The hosts responded to that early setback positively, with Sordell striking a fairly routine effort through to Green before Forsyth rose well to get on the end of a Mark Yeates cross from the right but the Scot was unable to keep his header down.

However, the Watford goal came under threat again in the 14th minute when Adrian Mariappa upended Jack Collison on the edge of the box, giving Taylor another opportunity to demonstrate his ability from dead balls, but this time he got too much whip on his effort and it went wide of Loach’s left-hand post.

Instead of going two behind, the Hornets were almost level twice within a space of a minute.

First Sordell did well to wrong-foot Tomkins on the left side of the area before hitting a rising right-footed curling effort that was destined for the top corner until Green superbly tipped it over with his outstretched left arm.

Then, from the Hornets’ first corner of the match, a downward header from John Eustace was certain to test Green again until it struck Sordell, with Chris Iwelumo wrongly deemed to have put the rebound over when the last touch came off an opposition defender.

However, it needed a fine, last-gasp challenge to prevent Winston Reid from potentially doubling West Ham’s advantage in the 26th minute after Cole had flicked on Collison’s lofted delivery from the byline towards the near post.

Back came Watford, with Forsyth doing well to win a race with O’Brien down the left before playing in Sordell, whose pace took him away from two defenders but his cut-back was behind Iwelumo.

Sordell warmed Green’s gloves with another decent effort as a whirlwind opening half-hour came to a close before Iwelumo also tested the England keeper with a low header after Eustace ducked under a Yeates corner from the right.

West Ham though, finished the opening half strongly and had an excellent chance two minutes before the interval when Collison came in at the back post to meet a deep cross from the left but he was unable to keep his header down.

The visitors had another great opportunity soon after when they broke swiftly on the counter and Cole was played in but, as the England striker closed in on goal, he was put under pressure and Loach did well to come out, narrow the angle and make the save.

But there was to be no third escape for Dyche’s men as West Ham doubled their lead in the second minute of injury time.

It initially looked the Hornets had dealt with the danger when O’Brien’s initial effort from the edge of the box was blocked but the ball broke nicely for the right-back and he steered a left-footed effort wide of Loach to make it 2-0.

The hosts had the first opening of the second period when an off-balance Iwelumo headed a Forsyth cross from the left tamely wide.

The next chance was largely the own making of the impressive Sordell, showing good control on the edge of the area before hitting a right-footed snap-shot that squirmed from Green’s but, fortunately for him, went wide, after Dickinson and Forsyth had been involved in a left-sided build-up.

Iwelumo’s disappointing evening came to an end in the 56th minute when he was replaced by Gavin Massey.

The game then went through a quiet spell, with West Ham largely content to sit on their winning hand, while their opponents had the bulk of possession but were unable to create too much with it.

The Hammers made their first change with 68 minutes on the clock as Abdoulaye Faye came on for Tomkins and then Green made a routine stop from a Forsyth strike from the edge of the box.

The visitors had not managed an effort on goal in the second half, but that all changed two minutes later when they put the game to bed.

Kevin Nolan received the ball on the left side of the box and fed the overlapping Herita Ilunga and his low cross left Cole with the simplest of finishes to make it 3-0 and finish off the neat build-up.

That was to be the scorer’s last involvement as he was replaced soon after by Piquionne, while Troy Deeney came on for Yeates. Julien Faubert also entered the fray moments later for Collison.

Parker wasn’t far away from making it 4-0 with seven minutes remaining when his right-footed piledriver hit the supporting post behind the goal.

A far better chance came moments later when Adrian Mariappa’s attempted clearance following a ball in from the right hit Martin Taylor and sat up nicely for Nolan, but he put his half-volley on the turn over.

But Parker did get the goal his performance merited as 90 minutes ticked by, curling a fine left-footed finish past Loach.

Watford: Loach; Doyley, Mariappa, Mar Taylor, Dickinson; Yeates (Deeney 74), Jenkins, Eustace, Forsyth; Iwelumo (Massey 56), Sordell. Not used: Gilmartin, Bennett and Mirfin.

West Ham United: Green; O’Brien, Tomkins (Faye 68), Reid, Ilunga; Collison (Faubert 75), Noble, Parker, Matt Taylor; Nolan; Cole (Piquionne 74). Not used: Barrera and Boffin.

Bookings: Noble for dissent (86).

Attendance: 14,747.

Referee: Dean Whitestone.