The goals took the 22-year-old winger's tally to 13 in 13 games - and in this form he looks well on his way to beating last season's total of 23.
Ronaldo's goals come in all shapes and sizes and his first after ten minutes was a superb effort with his right foot.
Ryan Giggs' corner to the near post was headed on by Nemanja Vidic and the ball went to Simon Davies who was under no pressure on the edge of the Fulham penalty area.
But instead of heading clear, Davies nodded the ball back into the centre of the box. Vidic again got his head to the ball and laid it to his left where Ronaldo met it with a stunning right-foot volley which fizzed into the top corner in the net from eight yards.
Despite a spell of dominance, United had to wait until the 58th minute before doubling their lead.
John O'Shea's throw on the left went to Giggs who returned the ball to the Republic of Ireland international.
O'Shea crossed to the far post where Ronaldo outjumped Dejan Stefanovic and glanced his header in from six yards.
Ronaldo should have had the opportunity to make it a hat-trick 11 minutes from time.
Played through the Fulham defence by Louis Saha's incisive pass, Ronaldo was brought down by goalkeeper Antti Niemi in the box as he tried to round the Finnish shot-stopper and score.
But, instead of awarding the penalty and dismissing Niemi, referee Rob Styles booked Ronaldo for diving.
If it had not been for Niemi, United would have easily beaten the five goals they scored against Fulham in the corresponding fixture at Old Trafford last season.
Niemi made a string of magnificent saves with Carlos Tevez the man to suffer most from his brilliance.
Niemi's best efforts came early on when he somehow managed to keep out the Argentinian's vicious 12-yard effort.
But the best of his saves came soon after when he kept out a point-blank effort from Tevez with a combination of his chest, arms and face.
Fulham's best spell came after the half-hour. United goalkeeper Edwin Van der Sar made his only real save of the game when he dived across his six-yard box to tip behind a powerful 20-yard drive from Danny Murphy.
Shefki Kuqi placed a free header over the bar just before half-time and Fulham had good claims for a penalty turned down when Clint Dempsey was barged over by Wes Brown in the United box.