Wayne Rooney started the match sporting unusual protective gear to cover his head wound. But there was no place in the starting line-up for Marouane Fellaini, who had to make do with a spot on the bench as David Moyes went with Anderson in midfield.
The first-half was dominated by the hosts, though without really threatening Julian Speroni's goal. Rooney was lively playing off Robin van Persie, but United struggled to carve out any serious chances behind Palace's rearguard.
It was no surprise that United needed ref Jon Moss' intervention to make the breakthrough on 42 minutes.
Ashley Young was bundled over in the Palace box for a penalty, which Van Persie duly converted to send a relieved United into the dressing rooms 1-0 ahead. It was a double blow for Palace, which saw Kagisho Dikgacoi sent off for the foul.
The second-half sparked into life 15 minutes in as Moyes handed debuts to Belgian pair Fellaini and Adnan Januzaj.
It was Januzaj who was the catalyst for United's second as he won a free-kick deep inside the Palace area.
Rooney was happy to take the responsibility and curled in a wonderful effort to put United 2-0 ahead.
Jimmy Kebe soon after joined Jerome in making his Palace debut. But down a man, the game was well beyond saving for the visitors.