Richards insists Ferguson will endure sleepless nights for some time to come after being taught a harsh lesson by Roberto Mancini's in-form side.
The right-back said: "People call us the noisy neighbours but here we are. We have a good set of lads and we want to show people what we can do.
"I think we did that today and it's what dreams are made of.
"We all know how good United are and how good they are at home, but they know about our attacking force — Balotelli, Dzeko, Aguero and Silva.
"To come to Old Trafford and win gives confidence, especially the way we won. We'll only go forward now."