He told ESPN: "It was quite a game. The first half we never started, didn't get into the game.
"From there we were just playing against the wind. The second half we played fantastic, just trying to get something from the game, and I think we were very unlucky.
"I think the attitude changed, that was the important thing. Wayne's (Rooney) ability does help but the attitude of the players was excellent everywhere on the pitch."
United had a host of penalty appeals turned down, with both their goalscorers going down under challenges in the area and handball shouts against both Sandro and William Gallas.
"There were quite a few," said Ferguson. "I think the one in the first half was a clear penalty kick, but maybe Nani made a meal of it and he didn't need to do that. He was clearly pulled back.
"The ones in the second half, I'm not so sure."
Watch: Tottenham stun United at Old Trafford... More Videos