West Ham overcame the pet hates of Kurt Zouma and recorded their first Premier League win for almost a month thanks to a deflected strike by Jarrod Bowen.
They were far from convincing against a newly resolute Watford team, clearly improved by the arrival of Roy Hodgson.
They spluttered but found a way to win just as they did at Kidderminster Harriers in the FA Cup when once again they had Bowen to thank for sparing them the ignominy of penalties against a team from the National League North.
Here, at the London Stadium, Bowen struck midway through the second half to keep the pressure from David Moyes, who really needed a win avert a form dip, an empty transfer window and the outrage sparked by the video clip of Zouma kicking and slapping his cat.
Bowen has become one of his reliable sources of inspiration and here his low drive swerved and wrong-footed Watford goalkeeper Foster with the help of a deflection.
He was close to a second in the closing minutes, denied by Foster who turned his effort against a post.
Watford are still searching for their first win since they beat Manchester United in November but they will take encouragement from being tougher to play against under Hodgson than they were under Claudio Ranieri.
Moyes with eyes on the top four, stuck with Zouma. Fresh in his mind perhaps the performance of Issa Diop at Kidderminster Harriers in the FA Cup. Diop struggled to contain strikers from the sixth tier before he was hauled off at half-time so Zouma and Craig Dawson were selected to start in the centre of defence.
The Watford fans went after him like RSPCA vigilantes, jeering is every touch and chorusing a variety of insults. When he rolled around hurt after challenging Josh King, they sang, “That’s how your cat feels.”
Although nothing quite as creative as the wit on social media who reworked the West Ham anthem to say “I’m forever booting tiddles”. Most of the home crowd were broadly supportive, and produced a loud cheer when he turned out of trouble in the opening minutes.
Of more concern for West Ham boss Moyes would have been the worrying signs on the pitch, and vulnerability at the back on the counter attack.
Tom Cleverley won the ball cleanly from Declan Rice and the yellow shirts poured forward, midway through the first half. Hassane Kamara overlapped and crossed from the left and Juraj Kucka arrived at the back post to plant a free header wide.
Hodgson threw his hands onto his head. It was a wonderful chance to establish an early hold on the game, and offered encouragement for the new Watford manager, whose impact is already clear to see in the shape and organisation of his team.
Moussa Sissoko missed the target with another chance, from the edge of the penalty area before the home side found a better rhythm.
Tomas Soucek climbed high to reach a corner but headed over and Said Benrahma went close twice in a matter of seconds. First, forcing a strong save from Ben Foster, then collecting the rebound and rattling the outside of a post from the tight angle.
Benahma volleyed another effort over, early in the second half, when Watford failed to clear a long throw and the ball bounced into his vicinity.
Without fluency or urgency, the game drifted on, littered with errors and the atmosphere remained subdued. There was a roar to greet the introduction of Manuel Lanzini on the hour. The game required a shot of quality.
As in the first half, West Ham generated some momentum as the half went on. Rice became more influential and Bowen broke the deadlock, collecting a pass from Lanzini, turning and firing low past Foster with the help of a heavy deflection off centre-half Samir.
Watford reacted. Tom Cleverley fired over after a powerful run by King and then then tested Lukasz Fabianski with a curling effort but there was no way back and they remain stuck in the bottom three.