The game only went ahead after three pitch inspections, and even then it was played in incessant rain, but the Hornets coped with the tricky conditions the better to secure the points through their top scorers, Tommy Smith and John-Joe O'Toole, either side of Clinton Morrison's equaliser for the visitors.
After a goalless first half, Watford took the lead from the penalty spot after 62 minutes when Elliott Ward tripped Tamas Priskin in the area and Smith confidently tucked away his 12th goal of an increasingly productive campaign.
However, the home side's joy was to be short-lived. The Hornets failed to clear their lines from a corner allowing Jay Tabb to fire in a shot through a crowded penalty area that looked to be going in anyway, but Morrison made sure from close to the goal-line.
That setback might have knocked the stuffing out of Watford during the last weeks of previous manager Aidy Boothroyd's reign, but the Hornets began to rediscover a mental toughness under caretaker boss Malky Mackay and have continued to build on that under Brendan Rodgers.
The outcome was Watford retook the lead five minutes after being pegged back.
Substitute Theo Robinson tried to get on the end of Lee Williamson's cross from the right, but Coventry only succeeded in half-clearing the ball to O'Toole, who celebrated his return to the starting line-up by emphatically firing his eighth of the season past Kieren Westwood.
Watford are still not out of the woods yet at the wrong end of the table, but they can look ahead to the second half of the season with more confidence than looked likely a few weeks ago.