The eventual 4-0 score line looked unlikely when Javier Hernandez saw his hastily awarded penalty saved by the Wigan keeper.
But after the break things started to look up for the hosts as two players making their debuts, Alexander Buttner and Nick Powell both chalked up goals.
Speaking to BBC Sport, Ferguson said: "We had to start all over again after the missed penalty.
"They slowed the game down a lot, but we weren't playing at the speed we play at. The second half we did after becoming more aggressive and played some penetrating football.
"Wigan play a a system which is difficult to play against. It is a good result."