Fergie said: “The Arsenal result was a big blow for us but we have come back and kept playing our football.
“If we are true champions, and I believe that we are, we will storm back to show our real worth.
“We have done it before and we will do it again.
“I believe there is a fresh intensity and a fiercer competitive edge this season that is going to provide a few more ups and downs before this championship is decided.
“So we will have to be strong, and make sure we are in fact stronger than any of the others. And I believe we are.
“We kept the pace and tempo when Portsmouth started to tire.
“I always thought we were in control of the game and in the second half we got into top gear. With the experience Portsmouth had in the team it was never going to be an easy game.
“But I’m pleased we’re through to the next round and a home draw is all you can hope for.”
