While Wayne Rooney, Carlos Tevez and Louis Saha may be seen as the men to bring in the goals for the Red Devils, the message is forget Ronaldo at your peril.
The 22-year-old Portuguese winger, who scored 23 goals for United last season, took his tally for the current campaign to ten with another double at Old Trafford.
It was the third time this season that Ronaldo has scored twice in a game and, when his strength in the air and powerful shot are combined with his trademark trickery, his scoring prowess is no surprise.
Although Ronaldo was the hero of a win which took the champions back to the top of the Premier League - albeit only likely until Arsenal play Reading on Monday night - this was a victory carved from a solid all-round performance.
Striker Tevez was in brilliant form up front and was unlucky not to score a brace himself and he received excellent support from Saha.
Tevez was denied United's opener in the sixth minute when Blackburn goalkeeper Brad Friedel was forced to dive across goal to beat away the Argentine's fierce 25-yard shot.
Blackburn were unlucky not to break the deadlock themselves after 19 minutes.
Ronaldo was robbed by David Dunn when he tried to dribble the ball out of his own box and it fell for Christopher Samba to hit a rasping 25-yard shot which crashed against a post.
But Blackburn's resistance was broken with two goals in 90 seconds.
In the 34th minute, Ryan Giggs fired a corner deep into the Blackburn box.
Ronaldo rose above Aaron Mokoena to head home from eight yards at the far post - the ball going in off the underside of the bar beating David Bentley's desperate bid to clear on the line.
Ninety seconds later, United made it 2-0 from a glorious move.
Rio Ferdinand's long ball out of defence was met by Brett Emerton, but the Blackburn man's header fell to Saha.
The Frenchman fed Tevez on the left and his tremendous run ended with a glorious pass across the box with the outside of his boot for Ronaldo to guide the ball home right footed from ten yards on the far post.
Blackburn's woes were compounded eight minutes into the second half when Dunn was sent off by referee Chris Foy.
Booked in the first half for obstructing Tevez, Dunn received his marching orders after a clumsy foul on Saha.
United had further chances to score, although Blackburn came closest two minutes from time when Samba's header from a Bentley corner was well saved by goalkeeper Edwin Van der Sar, with the ball being kicked clear out of his hands by Patrice Evra.