This was the Red Devils' 14th straight League and Cup win over Villa and it was executed by current champions who look odds-on favourites to retain their title.
It looked ominous for Villa as early as the 11th minute when Ronaldo's sprint across the edge of the box ended with his shot being turned behind for a corner by goalkeeper Scott Carson.
Six minutes later, their Portuguese star pulled another gem from his mine of outstanding goals.
Ryan Giggs' corner into the heart of the Villa box spun off Wilfred Bouma to Ronaldo, ten yards out, and he scored with the most audacious of right-foot back-flicks - the ball going through Martin Laursen's legs on its way into the net.
United made it 2-0 in the 33rd minute from a glorious move.
It was started and finished by Carlos Tevez when he found Paul Scholes in the centre.
Scholes blasted his pass to Ronaldo coming up on the right side of the Villa penalty area and his pinpoint cross to the far post saw the flying Tevez score with a free header from six yards.
If the first half had been good in atrocious conditions the second proved magnificent with the weather deteriorating rapidly.
United's third goal came eight minutes after the restart.
It followed another United chance when Ronaldo's close-range effort had been turned over via the bar by Carson's legs.
Villa never really recovered with Giggs' pass being brilliantly flicked into Rooney's path by Ronaldo and the England man turned home his left-foot shot from ten yards out.
Rooney hit the Villa post in the 68th minute when another incisive United move involving Giggs and Tevez created the opening for the United striker.
But, two minutes later, it was 4-0 as Giggs found Anderson, who turned the ball onto Ronaldo and his pass to Rooney, on the left-side of the box, was side-footed home right-footed by the England man from 12 yards.
Villa's last chance of the game came in the 56th minute when Shaun Maloney's rasping drive from the left side of the United penalty area was turned onto the bar and over by goalkeeper Tomasz Kuszczak.