Ferdinand, who scored in the romp, said: "The first half was a bit stop-start, we didn't finish our chances and were frustrated.
"We got a bit of a telling-off at half-time but came out and produced the goods."
Ferdinand was full of praise for hat-trick hero Cristiano Ronaldo.
"He's been doing it for two years now and long may it continue. When you need a goal it seems him, Wazza (Wayne Rooney) or Carlos (Tevez) get us out of it.
"It's about time he had a hat-trick and he's done it today."