Jesse Marsch's side found themselves with a mountain to climb inside half an hour when Luke Ayling was shown a straight red after a quickfire brace by Eddie Nketiah gave the hosts an early, comfortable lead.
With ten men, United put on an admirable showing to chase a result after the interval but Diego Llorente's second-half goal proved only a consolation as the Whites failed to find an equaliser in North London.
The defeat allowed Everton to climb out of the relegation zone with a 2-1 victory at Leicester City, causing the Whites to drop below the dreaded dotted line, level on points with 17th-placed Burnley but with a significantly poorer goal difference than their Lancashire counterparts.
Graham Smyth, the YEP's chief football writer, hands out the scores from Sunday afternoon's clash at the Emirates.
The defeat allowed Everton to climb out of the relegation zone with a 2-1 victory at Leicester City, causing the Whites to drop below the dreaded dotted line, level on points with 17th-placed Burnley but with a significantly poorer goal difference than their Lancashire counterparts.