Sir Alex Ferguson admits Manchester United had to dig deep on Monday in order to edge out Blackburn and stretch their lead at the top of the Premier League table to five points.
The Red Devils left it late at Ewood Park before wrapping up the win, with Antonio Valencia and Ashley Young finding the target in the last 10 minutes to seal a 2-0 success.
It had looked for long periods as though relegation-haunted Blackburn would be able to frustrate their North West neighbours and pick up a valuable point of their own, but United are past masters when it comes to grinding out result at the business end of the season.
Ferguson told Sky Sports: "It was a long night wasn't it? We just had to persevere and persevere and we got our rewards for it.
"We weren't really making any clear cut chances - Wayne (Rooney) had a good free-kick that was saved by the goalkeeper and there were a lot of great crosses by Antonio that weren't finished off.
"We always had them under the cosh, we just had to be careful of the counter attack because they were dangerous at that point."
While United can breathe a little easier after putting clear daylight between themselves and arch-rivals Manchester City, Ferguson was just as happy to add another two goals and a clean sheet to his team's tally for the season.
Asked for his take on how the title race is shaping up, the Scot said: "We have scored more goals now and I think that's a big step forward for us, from a deficit of about 18 and it's now only one.
"It could come to goal difference, who knows? Now we have scored more goals than City, it's significant that because we look as though we can score.
"We have 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 try and win Sunday's game (against Queens Park Rangers)."
One man who has played a leading role for United over recent weeks, as they have surged clear at the summit, is David de Gea, with the Spanish goalkeeper having put his early-season troubles behind him to become a reliable last line of defence.
After seeing his young shot-stopper shine again at Ewood Park, Ferguson said: "The progress is obvious, everyone can see that the boy is growing in stature and confidence and he's always had great ability.
"He made three great first half saves and that was the kind of threat Blackburn presented to us, this counter attack they do. They do long balls and they all get on top of the ball and they're dangerous at that, they're very dangerous.
"David has kept us in the game, because in the first half even though we hit the post and had a penalty kick claim, we had a lot of possession, but to get that goal was difficult with the way Blackburn defended so deeply."