Wayne Rooney then levelled matters and United had to be content on leaving a snowy Teeside with a single point.
"We could have lost the game there's no question - they had some chances. At times the defending was a bit haphazard I thought," Fergie said after the match.
"But in other ways we could have won the game because some of the approach and football was very good. At 1-0 we looked very strong.
"We controlled the game and Wayne Rooney was unluckily given offside when he clearly wasn't."
"They changed their formation to a 4-4-2, got an equaliser, and it was a great game of football after that."