The young Reds created plenty of chances at Kingsmeadow and forced Blues goalkeeper Ted Curd into several good saves, but were hit twice on the break before half-time.
Starting with intensity, United created the game’s first chance when Gabriele Biancheri’s low drive — from a Jack Fletcher cross — was denied bravely by the out-rushing Curd.
Harry Amass then centred for Tyler Fletcher, whose right-footed effort was blocked, allowing Chelsea to launch a counter-attack. The Blues showed a clinical edge that United had lacked when Kavuma-McQueen drove one in from 25 yards.
Curd once again prevented Biancheri finding the back of the net, this time after the Welsh striker attempted to chip the Chelsea ‘keeper when being fed through nicely by midfielder Finley McAllister.