United's U18s suffered a five-goal drubbing at the hands of local rivals Manchester City on Tuesday afternoon.
Four second-half goals did the damage for the table-topping Blues, who were always in control of a one-sided match at the Cliff.
Both sides observed a minute's silence before kick-off in recognition of the 50th anniverary of the Munich air disaster.
It was City who quickly established superiority, however, and were a goal up at half-time through Donal McDermott's strike.
After the break, however, City ran riot and scored again through Dedryck Boyata, a David Ball penalty and a brace from Robbie Mak.
United had only one meaningful effort all match, a shot from Anton Bryan which was well kept out by City stopper Greg Hartley.
The match was the first of three meetings between the two clubs this week, preceding the Reserves' Manchester Senior Cup clash on Thursday and Sunday's senior Premier League meeting at Old Trafford.