Kenny Jackett was full of praise for in-form Millwall striker Darius Henderson, while Andy Thorn blasted Coventry's second-half display.
After a goalless first period, former Sheffield United frontman Henderson netted in the 53rd and 69th minutes to put the Lions firmly in control at the Den, with Liam Feeney wrapping up the victory late on.
Henderson has now bagged six goals in three games for Millwall, including a hat-trick over Leicester 10 days ago, having gone through a barren spell since scoring twice in Millwall's first two league games.
Jackett is delighted with the form of his summer signing, saying: "Darius has made a great start to his Millwall career, he is in great form at the moment and has played very well for us so far.
"Every signing is a gamble and finding centre-forwards for the Championship is a big call. It is very tough and I would agree it was a risk.
"When I met him I was convinced he wanted to come back down south for family reasons and I felt that would help and he would be a lot more settled.
"He has given us a presence and a quality because he can bring people into play as well and when you get the ball in the box he is a threat.
"He occupies defenders, he has got some presence and for us this season he has been a big player and he finished well again. The combination of Darius and Jay Simpson has been a good one and has looked a threat."
At a loss
Coventry boss Thorn admitted he was at a loss to explain the Jekyll-and-Hyde nature of the Sky Blues' performance.
"I can't understand how we can play the way we did in the first half and turn in that sort of performance in the second," said Thorn.
"That's probably why the players are in this league, because if they were consistent and played the way they did in the first half in the second we would have won the game - I just don't understand it.
"It was like two different sides were playing out there and when people start to think they are individuals you have got problems. Our second half performance was unacceptable - to turn in a performance like that was amateurish.
"We had a few chances in that first half, we felt comfortable and we felt we had more gears to go into. I'm sick of hearing excuses and people having opinions that aren't right, I know what's right and the players will do what we say or they won't be playing."