The Red Devils scored all five of their spot-kicks in front of 61,000 fans in the US capital as they came up against former captain Nemanja Vidic, who joined the Serie A side earlier this summer.
New manager Louis van Gaal hailed the performance as the best of his short reign so far, saying: “I am very pleased. I think we played by far the best match of our sequence of three.
“They only had one shot on our goal and that was given by the referee [a free-kick], but I think we also created six or seven chances, so then it is seven against one.
“I was very pleased with our ball possession; it was much better than the other matches. And I think also the positions were better covered.”
Here are some of the best pictures from Tuesday’s game in the United States.
MORE: Man United latest news
MORE: Arsenal latest news
MORE: Chelsea latest news
MORE: Liverpool latest news