They went a goal down after a minute - but then rattled in four in the next quarter of an hour.
The Sky Blues simply couldn't recover and Blues extended their advantage after the break until the hosts netted the game's last two goals.
Rico Patterson and Jobe Bellingham both scored twice for Blues and there was one apiece for Amari Miller, Marcel Oakley and George Hall.
Patterson got Blues level in the fourth minute, with a low right foot finish, after Josh Williams moved the ball into Miller, who played it round the corner to the right of the area quickly.
Five minutes later Blues had the lead when Miller smacked in a sidefoot volley at the far post after a corner got flicked on and arrived in his space.
Patterson got his second in the 12th minute, moving onto a ball angled into the box from Miller to prod past the 'keeper from close range. It culminated a fine passing move by Blues that started on the right of their own area.
Right-back Oakley got in on the act in the 16th minute. Again Blues flowed from the back to the front, with Williams helping a clipped ball over the top by Alfie Chang past the oncoming 'keeper for Oakley to slide in from the right of the area.
Four minutes before half-time Blues were 5-1 to the good. They carved Coventry open on the right when Remi Walker played a short pass in for Oakley who pulled the ball back from the byline for Bellingham to slot firmly into the bottom corner from eight yards.
Bellingham's second came in the 57th minute. A right wing corner was headed powerfully towards goal by Rico Browne and there was Bellingham to help it on its way into the roof of the net, with a close-range header.
Blues seventh goal came courtesy of George Hall, who turned sidefooted in a low cross with a pirouette after Miller made a dart to the byline on the left (71 minutes).
Blues: Clayton, Oakley, Djurovic (Scanlon ht), Kade, Browne, Chang, Walker, Williams (Hall 65), Patterson, Bellingham (Sullivan 65), Miller.