Kaka turned his side's dominance into goals with a fine volley on 11 minutes, while Clarence Seedorf thumped home a volley from the same position on the half hour mark as United were left dazzled by
Substitute Alberto Gilardino wrapped up the 5-3 aggregate win with a breakaway goal in the closing stages to seal
Though Kaka had been singled out by all and sundry as the main threat United had to nullify, the Brazilian found himself in space time and again in the opening stages, and orchestrated
For a player returning from a month's injury lay-off, the sight of the midfield maestro bearing down on you in full flight in the first minute of your comeback is unlikely to be a welcome one, yet one that befell Nemanja Vidic.
With under 60 seconds on the clock, Kaka picked the ball up in space, flew past Vidic on the outside, and flashed a dangerous ball across the face of goal that could easily have resulted in a goal had Pippo Inzaghi held his run just a little longer.
With the rain teeming down, United appeared all at sea, and were duly carved apart again as another flurry of crisp passing in the
United's inability to keep possession and apparent refusal to guard Kaka meant the first goal was only a matter of time, and indeed it was the Brazilian who scored it, volleying home from the edge of the area after a gorgeous backward header from Seedorf.
The comparisons drawn in the pre-match build-up between Kaka and Cristiano Ronaldo looked laughable as the former left United's defence floundering with his pace and movement. The Portuguese, starting on the left of midfield, endured a nightmare, and was marked almost out of the game by the excellent Gennaro Gattuso. On the few occasions he did escape his marker, his passing was wayward.
Ronaldo's evening was summed up neatly soon after the break when he inexplicably gave the ball straight to Kaka in midfield, who once again charged at Vidic. A burst of pace and a shimmy later, he was lining up a left foot shot that Van der Sar did well to parry clear.
Marek Jankulovski released Gilardino, who had the freedom of the United half to bear down on Van der Sar and pick his spot low to the Dutch goalkeeper's left.
Ronaldo picked up a booking late on for clattering into Massimo Ambrosini, and misses his side's next Champions League match, which will be their first group game at the start of next season.