Watford 0 West Ham Utd 4

West Ham breezed to victory with a thoroughly professional performance against Watford at Vicarage Road tonight.

Sam Allardyce's United, who enjoyed a first win of the season at Doncaster on Sunday secured the club's first back-to-back away wins since 2007 against a disappointing Hornets side in tonight's Championship clash.

The writing was on the wall for the home side as early as the third minute when centre-half James Tomkins pounced on Matt Taylor's corner to direct a powerful header beyond Watford goalkeeper Scott Loach.

The second goal arrived with the half time whistle rapidly approaching; full-back O'Brien burst past half the Watford team before firing beyond Loach at the second attempt after the 'keeper had palmed away his initial effort.

Carlton Cole added the third of the night when he converted a Herita Ilunga cutback from close range with 20 minutes remaining. Finally, Scott Parker wrapped up a comprehensive win for the Hammers with a neat finish having combined well with sub Julien Faubert to send the Hammers into third place in the fledgling Championship table.

Sam Allardyce began the game with just one change from the team that won at Doncaster 48 hours ago. Carlton Cole came in for Frederic Piquionne, whilst Herita Ilunga kept his place in the starting XI despite having been tipped to be dropped after a disappointing start to the season.

Overall it was a comfortable evening for the Irons, although there were one or two scary moments in the first half. Robert Green was at full stretch to deny Sordell hitting the target with a curling 16th minute effort before Carlton Cole was forced to hack one effort of the line.

Had either of those chances been converted it could have been a quite different game. However O'Brien's goal - his first for West Ham and only the third of his career - effectively ended the game as a contest and West Ham strolled to victory thereafter.

Whilst tougher challenges than that presented by the Hornets tonight will inevitably follow, the win will be a huge confidence booster ahead of this weekend's clash with Leeds United.

Watford 0 West Ham Utd 4: match facts

West Ham Utd: Green, O'Brien, Ilunga, Tomkins (Faye 68), Reid, Noble, Parker, Nolan, Collison (Faubert 75), Taylor, Cole (Piquionne 74).

Subs not used: Boffin, Barrera.

Goals: Tomkins (3), O'Brien (45+2), Cole (70), Parker (90+1).

Watford: Loach, Dickinson, Mariappa, Taylor, Doyley, Yeates (Deeney 74), Eustace, Jenkins, Forsyth, Sordell, Iwelumo (Massey 56).

Subs not used: Gilmartin, Bennett, Mirfin.

Referee: Dean Whitestone.

Attendance: 14,747.