The Sky Blues tasted defeat for the second time in four days as Watford ran out deserved winners at the Ricoh Arena.
Clinical first-half strikes from Adam Johnson and Marlon King did the damage before Darius Henderson put the result beyond doubt seconds after the interval.
Kevin Kyle saw a header cleared off the line and Michael Mifsud fired narrowly wide but City were second best to a clinical performance from the Championship pacesetters.
City boss Iain Dowie made two changes for the visit of the high-flying Hornets with David McNamee replacing the injured Michael Hughes on the right of midfield and Kyle starting in attack ahead of Robbie Simpson.
Stephen Hughes flashed the game's first effort on goal wide from a long-range free-kick with just three minutes on the clock while a speculative volley John-Joe O'Toole from similar distance also whistled past the post at the other end soon after.
The Sky Blues had a combination of goalkeeper Andy Marshall and the post to thank for keeping the scores level as Watford went perilously close to breaking the deadlock in the 19th minute.
Hornets striker King robbed Elliott Ward for pace to reach a long ball over the top but Marshall spread himself well to block the initial shot with his legs before King sent the rebound crashing against the outside of the woodwork.
And Marshall had to be at his best again three minutes later as he reacted superbly to turn away O'Toole's low effort from point-blank range.
Gary Borrowdale was then forced to leave the action on a stretcher after emerging worse off in a challenge. Arjan de Zeeuw replaced the City full-back with Ben Turner swithing to Borrowdale's left-back berth.
But Watford continued to apply the pressure and they got their reward on the half hour when King latched onto a loose ball on the edge of the area and laid the ball off for Adam Johnson, on loan from Middlesbrough, to arrow a low effort beyond Marshall.
Julian Gray sent a cross fizzing across the face of goal as City launched their response and Kevin Kyle sent a header wide from an Isaac Osbourne cross.
However, they found themselves with a mountain to climb three minutes before the interval when the dangerous King latched onto a loose ball in the area and coolly fired into the net on the turn.
And to make matters worse, they added a third straight after the restart when King found Darius Henderson, who got in between de Zeeuw and Ward before unleashing a powerful drive which left Marshall with no chance.
Kyle then saw a header cleared off the line by O'Toole before crossing for Robbie Simpson, a half-time substitute for the injured Stephen Hughes, to head over as City looked for a route back into the match.
But Watford were still looking dangerous on the break with Danny Shittu sending a left-foot rocket from 20-yards flying narrowly wide of the top corner and Marshall racing off his line to smother the ball at the feet of Henderson with 20 minutes remaining.
Another excellent stop from Marshall then prevented Henderson's replacement, Tamas Priskin, grabbing a fourth goal as the Hungarian raced clear of the offside trap.
City continued to pose questions to the Hornets' backline in hope of a consolation as the largely ineffective Mifsud lashed narrowly wide from 25-yards before another substitute, Leon Best, scooped over at the back-post.
Best then forced Watford 'keeper Richard Lee into his first notable save of the match in the 88th minute and there was still time for Mifsud to drag a shot wide.
But a goal didn't come and consequently, the Sky Blues slip into the bottom half of the Championship table.
Coventry: Marshall, Osbourne, Ward, Turner, Borrowdale (de Zeeuw 26), McNamee, Doyle (c), S Hughes (Simpson, 46), Gray (Best, 72), Kyle, Mifsud. Subs: Adebola, Tabb.
Goals: None
Booked: McNamee (foul), Turner (foul)
Watford: Lee, Doyley, Shittu, Demerit, Stewart, Smith (McAnuff, 58), O'Toole, Mahon (c), Johnson, King (Ellington, 79), Henderson (Priskin, 76). Subs: Loach (GK), Mariappa.
Goals: Johnson (30), King (42), Henderson (46)
Booked: Demerit (foul), Stewart (dissent)
Attendance: 17,032 (2,286 Watford)
