Marouane Fellaini was the two-goal hero for the hosts, while Juan Mata and Romelu Lukaku were also on target as United cruised to a sixth win from seven Premier League games. That record is now extended to seven matches.
Palace's wait for a goal went on, with Andros Townsend's free-kick flying just wide in their only opportunity in the closing stages, before Anthony Martial was impressively denied by Hennessey after being played in by fellow substitute Ander Herrera. Although looking strong on the ball going forward, the big Belgian missed a couple of chances throughout the match, giving way for other players to score.
"There is a long time to go", he added when asked about Palace's plight. Conversely, this is the seventh defeat for Palace, who are now at the bottom of the table.
- Crystal Palace have lost eight consecutive league games without scoring, the joint-longest run in English league history alongside Hartlepool (two occasions, 1970 and 1993) and Sunderland (1977).
Asked about his thoughts on playing in Russian Federation and then preparing for a Premier League match, he added: "I had concerns". It was the result I was expecting; we've won 4-0 a few times this season, we're doing this for fun now!
It was another fine afternoon for Manchester United at home to Crystal Palace on Saturday.
The visitors started off the game playing deep in their own half hoping to keep a tight game against the Red Devils.
Many expected the Red Devils to easily take apart the sudden relegation candidates and Fellaini duly obliged, grabbing himself a brace to complete a dominant performance.
It is a sign of his developing all-round game that Rashford has already surpassed the Premier League assist tallies he recorded in the past two seasons.