After a goal-less first half, Antonio Valencia finally made the breakthrough for the Red Devils in the 81st minute, when his drilled cross-cum-shot flew past Rovers goalkeeper Paul Robinson.
Substitute Ashley Young then secured a vital victory when he turned on the edge of the box and squeezed in a superb second to fire the defending champions five points clear of local rivals City at the top of the table.
“We just had to persevere and we got our rewards for it,” Ferguson told Sky Sports. “We weren’t really making any clear-cut chances.
“Wayne [Rooney] had a free-kick that was saved by the goalkeeper and there were a lot of great crosses by Antonio Valencia.
“We always had them under the cosh but we had to be [wary of being caught] on the counter-attack because they were dangerous at that.”
Reflecting on Valencia’s goal, Ferguson continued: “If you don’t try to shoot, you’re never going to find out if you’re going to score. It could have been a cross, it could have been a shot – it doesn’t matter.”
The Manchester United boss also reserved special praise for goalkeeper David De Gea, who made a string of fine first-half saves to keep out Steve Kean’s men and looks far more assured between the sticks compared to when the two sides met back on New Year’s Eve at Old Trafford.
“The progress is obvious and everybody can see that,” he continued. “The boy is growing in stature and confidence. He’s always had great ability.
“He made three great first-half saves and that’s the kind of threat the Blackburn offered. David kept us in the the game.”
The two goals at Ewood Park took United’s tally for the season to 76 – one more than Manchester City, whose goal difference is now only superior to their rivals by one.
And Ferguson believes that could be a crucial factor in the title race with just seven games left to play.
“We’ve scored more goals now and I think that’s a big step forward for us – from a deficit of about 18 to now only one,” he said. “It could come down to goal difference, who knows?
“We’ve still got seven games left and my experience of these situations is that it doesn’t matter what the points total is at the moment, what is really important is to win Sunday’s game [at home to QPR].”
Ferguson also reserved special praise for United’s travelling supporters at Ewood Park. He added: “They were fantastic, unbelievable. They deserved the result because they never stopped. They almost sucked that ball in.”
Meanwhile, Blackburn boss Kean was left to reflect on a gutsy but ultimately fruitless display by his side, who dropped down into 18th place on goal difference.
“For 80 minutes we gave it a really good go, their keeper’s had a very good night and he made some wonderful saves,” he said. “We caused a lot of problems on the break. We had to score our chances but we didn’t.”
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