In the end the 49th minute proved to be the magic moment when Darren Fletcher made the decisive first strike after a dreadful mistake by defender Jonathan Fortune who completely mis-kicked a clearance into the path of the midfielder.
With the obvious difference in class, the last thing Charlton had needed to do was present their visitors with such a gift and the match was virtually over as a contest from that point with United scoring twice more to ease home to a comfortable win.
Manchester United are the only team in the Premiership that Charlton have never beaten in their seven years in the top flight and their hopes of their first success were not helped even before the game started by the absence of summer signing Djimi Traore, who was serving a one-match ban, and injuries to defender Gonzalo Sorondo and midfielder Andy Reid.
United, buoyant after their 5-1 thrashing of Fulham on Sunday, were without the suspended Wayne Rooney and Paul Scholes.
Not surprisingly Cristiano Ronaldo was booed even in the warm-up and there were ironic cheers from the Charlton fans as he sent the first shot of the match wide.
The visitors created plenty of first-half chances, Ronaldo sending a free-kick over the bar and Ji-Sung Park going close on two occasions, first heading wide and then forcing a fine save from Charlton goalkeeper Scott Carson.
Ryan Giggs struck a sweet free-kick from just outside the penalty area for United, only to see his shot rattle the post.
The home side finally managed to put some pressure on the United defence, Darren Bent's header being saved at the foot of the post by Edwin Van der Sar and the home side had strong claims for a penalty when Wes Brown appeared to handle in the area.
Just before the break Giggs sent in a low shot which Carson turned away for a corner.
United turned the screw as they looked for an interval lead and Ronaldo 25-yard effort hit the crossbar and he then sent a close-range header wide.
After the break Charlton had a rare effort on goal when Darren Ambrose saw his shot shave the outside of the post.
Then came the breakthrough with Fletcher's goal, the youngster still having work to do after taking advantage of the defensive mistake.
The home side created their best chance of the game with 16 minutes left when Amady Faye's long ball was headed on by Marcus Bent and Darren Bent fired over the bar.
With 13 minutes remaining United introduced Michael Carrick for his Premiership debut, the ex-Spurs man having recovered quicker than expected from his pre-season injury.
United put the icing on their performance when Louis Saha chested the ball down, swivelled and fired a left-foot pearler past Carson.
The overworked Charlton goalkeeper then had to make a fine save to deny substitute Ole Gunnar Solskjaer but he had no chance with the Norwegian's shot in the last minute.