The Frenchman latched on to a sublime through-ball from Andreas Pereira to squeeze a shot past Paulo Gazzaniga and open the scoring in the 21st minute.
It was his second goal of Tour 2019, after netting from the penalty spot in our 4-0 win over Leeds United.
Martial was unfortunate to hit the post earlier with a left-footed shot and was lively throughout the first half, making many penetrating runs in behind the defence.
Tony lined up as the spearhead of a three-pronged attack, flanked by Mason Greenwood and Daniel James, before being replaced by Marcus Rashford at the break.