Dean Smith's hosts started positively, with Jack Grealish and Trezeguet both coming close.
But Bruno Fernandes opened the scoring for Man Utd with a penalty on 27 minutes, after he was fouled by Ezri Konsa.
Mason Greenwood doubled the lead with a fierce shot from the edge of the box in first-half stoppage time.
And Paul Pogba made it 3-0 after the break with a low, curling shot after Fernandes teed him with a corner kick.
Man Utd, in fifth position, are the first team in Premier League history to win four successive matches by a three-goal margin.
Villa stay 19th with 27 points, four points from safety.
Aston Villa: 12 July v Crystal Palace (H)
Man Utd: 13 July v Southampton (H)