West Ham United went down 2-0 at Watford as David Moyes' tenure as manager got off to a losing start after a goal in each half at Vicarage Road on Sunday.
Will Hughes turned home Andre Gray's scuffed shot in the 11th minute to put Marco Silva's men in front and Richarlison netted the second in the 64th minute to wrap up the points.
The visitors, who had struggled to get striker Andy Carroll involved, rallied after going behind and would have been level before halftime but for some fine saves by Heurelho Gomes.
After West Ham's Cheikhou Kouyate missed another glorious chance, Watford upped their game and the pressure told as they scored their second.
Watford climbed to eighth on 18 points, with West Ham stuck in the relegation zone in 18th on nine.
Moyes, taking charge of his first match since taking over from the dismissed Slaven Bilic, made three changes to the side soundly beaten by Liverpool, with Carroll returning.
The burly striker was immediately in the thick of the action, leaving Watford's debutant Marvin Zeegelaar in a heap in just the second minute after catching him with his elbow.
The Dutch defender was patched up and then played a pivotal role in Hughes' first goal in Watford colours.
His hoisted cross landed at the feet of Gray, who did not connect properly with his strike, but the ball kindly for Hughes, who turned to sweep it into the net.
The Hammers pressed only to find Gomes in remarkable form. He dived bravely at Kouyate's feet to smother his goal-bound effort before producing a sensational double save to twice deny Marko Arnautovic.
The visitors' profligacy continued after the break, Kouyate ballooning a strike from close range.
"We missed some big chances," Moyes said. "The better team won the game, but there was a chance to change the outcome."
In contrast to the heroics of Gomes, Hammers' England goalkeeper could perhaps have done better for Watford's second goal as Richarlison's shot squirmed past him.
Manuel Lanzini's shot was blocked on the line by Adrian Mariappa but Watford held out for only their second home win of the season to improve Silva's stock yet further.
The Watford manager is not publicly committing his future to the club with Everton still reported to be favourites to sign him for the vacancy at Goodison Park.
"My players know how committed I am," Silva said. "Some things in football you cannot control. Anything can happen."
(Reporting by Pete Hall; Editing by Ken Ferris and Ian Chadband)
