Mason Greenwood, Anthony Martial and Marcus Rashford, with an average age of 21 between them, were far too hot for the Serbians as they all got on the scoresheet to make it a stroll into the next stage for Ole Gunnar Solskjaer's side, ahead of the long-haul trip to Kazakhstan at the end of this month against Astana and the Old Trafford final group L game against AZ Alkmaar in December.
There was no shortage of early goalmouth action, though both managers would have been angry that it all came about largely through defensive sloppiness.
Both sides had goals chalked off in the first four minutes of the tie.