There wasn’t much ‘friendly’ about the match, with hard tackles flying in, and Dallas was forced to leave the action after he was accidentally caught in the face by Martial during the second-half.
Earlier in the match, Kalvin Phillips received a booking for a reckless challenge on Juan Mata, while Ashley Young smashed through Adam Forshaw in the game’s dying moments.
There were no injuries, though, despite the competitive nature of the clash, and Dallas was seen after the game with a bandage around his head.
Mason Greenwood and Marcus Rashford gave Man United a two-goal lead during a dominant first-half for the Red Devils, which also saw a fine performance from Paul Pogba.
Ole Gunnar Solskjaer made 11 changes at the break, while Leeds remained unchanged, and the fresh legs started to show.
Phil Jones powered home a header from a corner, before Martial cooly converted a penalty, which was excellently won by Man United youngster Tahith Chong.
