Man Utd welcome back Neville, Foster in Chelsea win
The fullback featured in reserve-team manager Ole Gunnar Solskjaer's defence as he continued his recovery from long-term injury problems, while fellow international Ben Foster played in goal.
But United, also boasting highly-rated Brazilian twins Fabio and Rafael in their team, took the lead against the run of play just a minute later.
Danny Drinkwater finished well from eight yards following a ricochet in the Chelsea area.
Jeffrey Bruma almost equalised for the Londoners with 13 minutes left but Jimmy Derbyshire blocked his header on the line, while Foster also saved two more powerful efforts by the lively Mellis.