The U's went top of League Two after a double from Tom Craddock saw them leave Southend at sea.
Wilder said: "It was another decent night's work for us, a really satisfying win.
"I thought we played really well, playing it from side to side. We know more than anyone how difficult it can be with 10 men for so long because it happened to us against Swindon last season.
"It just needed us to finish off a few more opportunities. But to have a fit and free-scoring Alfie Potter and a fit and free-scoring Tom Craddock is great for us.
"We had to try and get round the back of them and make the pitch as big as possible, and we did that in the second half. We kept shifting aspects of the play and were really patient at times."