David Moyes failed to inspire West Ham as their Premier League woes deepened with defeat in his first match in charge at Watford.
The Moyes era got off to the shakiest of starts when the home side took the lead in the first threatening attack of the game at Vicarage Road.
West Ham failed to deal with a cross from the left and, when the ball fell to Andre Gray, his mis-hit was finished off by midfielder Will Hughes for his first Premier League goal with 11 minutes gone.
The Hammers tried to hit back but Andy Carroll directed a tame header straight at home keeper Heurelho Gomes.