Mileta Rajovic's double on his first Watford start was not enough to clinch victory as Coventry fought back three times to share the points in a thriller at the CBS Arena.
The Danish striker put the Hornets ahead 15 minutes after Daniel Bachmann had saved Matt Godden's penalty at the other end.
Milan van Ewijk levelled before half-time with a superb free-kick, but Udinese loanee Matheus Martins restored the visitors' advantage.
Bachmann's error led to a Wesley Hoedt own goal that made it 2-2, but Rajovic scored his second - only for Godden to equalise again for Coventry three minutes from time.
Watford began well and might have snatched an early lead when Imran Louza capitalised on a slip by goalkeeper Ben Wilson to set up Tom Ince, but his curling effort flew wide.
At the other end, Bachmann maintained parity, flinging himself to his right to push away Godden's spot-kick after Ryan Porteous was adjudged to have handled a Jay Dasilva cross.
It was the visitors who broke the deadlock 10 minutes before the interval, with Ince involved again as he collected Ken Sema's pass and set up Rajovic, recently signed from Swedish club Kalmar, to fire into the roof of the net.
The Hornets' lead lasted only six minutes as Coventry won a free-kick 25 yards out and Van Ewijk stepped up to hammer it emphatically into the bottom left-hand corner.
But they were back in front in the 52nd minute when Martins produced a skilful run on the left and worked his way past two defenders before curling a classy finish beyond Wilson.
The Sky Blues keeper was at full stretch to prevent Louza from making it 3-1 soon afterwards, but Bachmann then went from hero to villain as Hoedt's backpass trickled beyond him to gift the home side their second equaliser.
Watford responded with a raft of substitutions and one of them, Vakoun Bayo, broke to set up Rajovic for his second goal, a close-range finish 11 minutes from time.
It looked as if that would be enough to clinch a first win in four games for Valerien Ismael's side - but the impressive Haji Wright had other ideas, bursting down the right and setting up Godden to slam home and make it 3-3.
Coventry's third consecutive draw leaves them 14th in the table, a point and four places above Watford going into the international break.
Coventry manager Mark Robins told BBC Coventry & Warwickshire:
"There were too many decisions we made that were wrong but there were so many decisions that we made right as well.
"I thought we were brave, we went after the game all the time - we just got things wrong on the defensive side.
"Other than that, we created some brilliant chances and we've come back three times. The football was scintillating and the crowd were magnificent.
"There's a bit of confidence lacking in one or two areas but in the final third we looked dangerous, and we looked a threat from set-plays."
Watford head coach Valerien Ismael told BBC Three Counties Radio:
"I think that's a great reaction after losing two games, coming to Coventry - a really difficult away game.
"The second goal we conceded on our own, but we came back all the time and showed great mentality. The attitude of the players was really good.
We scored three great goals, Rajovic scored two and we stopped the bleeding after two losses.
"He's a number nine so he has to be in the box, this is why you pay for a striker, to score goals. I think he gives us more flexibility in our game as well."