Colchester manager Joe Dunne admitted he was surprised by Port Vale's team selection after guiding his side to a second successive 1-0 win in Sky Bet League One.
Gavin Massey netted the U's second-half winner to make it back-to-back league wins against a cautious Vale side.
Dunne said: "It was an interesting selection by Port Vale.
"When we saw their team sheet, it took us a little bit by surprise. We expected one or two changes, but he played a pretty defensive team, which was good for us.
"With the team I picked, the onus was on the front four to create and I thought that we saw that in the first 30 minutes or so.
"All we were short of were a couple more goals, but overall I was really pleased."
Vale manager Micky Adams admitted his side were not at their best after they fell to their first defeat since winning promotion from League Two.
Adams said: "To be brutally honest, we were poor.
"Obviously I picked the wrong side, but I am really disappointed with the performance.
"Next week I will change the side. I don't want to go overboard, but it was a poor performance."