Michael Mifsud's brilliant late strike earned Coventry all three points after another desperate display from them.
They were set for a fourth goalless game until Mifsud netted from 25 yards, before Colchester's Teddy Sheringham saw red for elbowing Michael Doyle.
After a poor first half, Coventry substitute Robbie Simpson's header was cleared off the line and home keeper Andy Marshall denied Kevin Lisbie.
But the only moment of genuine quality came from Mifsud and proved decisive.
Coventry assistant boss Tim Flowers:
"It is a relief. Our shape was better, we got a clean sheet and an opportunist bit of skill from Michael. You end up with three points and everything's rosy in the garden again.
"When the game gets a little bit stretched, you can pop it into Dele Adebola's body around the box. He's an unbelievably strong man and he has this ability to maul you and roll you around as a defender.
"We tried to mix it up a bit and see if Michael could have an effect down the middle. And, of course, he did."
Colchester boss Geraint Williams:
"Teddy did catch the lad and if an arm catches somebody in the face, you run the risk of getting sent off. I've got no contention with the referee's decision."
"That's as good as we've defended. It was going to take a bit of skill or a bit of luck and a deflection just took the shot away from our goalkeeper. It had 0-0 written all over it up until then.
"It was a great chance for Lisbie. That was one that we did carve out. That's the sort of thing that can turn the game."
Coventry: Marshall, McNamee, De Zeeuw, Turner, Hall, Mifsud, Osbourne, Doyle, Gray (Tabb 90), Kyle (Adebola 60), Best (Simpson 66).
Subs Not Used: Konstantopoulos, Cairo.
Booked: Kyle, Osbourne.
Goals: Mifsud 81.
Colchester: Davison, Duguid, Baldwin, Connolly, Elokobi (Virgo 87), Yeates, Jackson, Izzet, Granville (McLeod 55), Platt (Sheringham 60), Lisbie.
Subs Not Used: Gerken, Watson.
Sent Off: Sheringham (90).
Ref: Ray Lee (Essex).