United's reserves forced a 2-2 draw with a Liverpool side containing several players with first-team experience.
Nicky Ajose, who returned for a run-out with the Reds before ending his loan spell at Bury, saw his early goal overturned by Jonjo Shelvey and Joe Cole's drive that deflected off team-mate Nikola Saric. However, Warren Joyce's men secured a point when Gabriel Obertan hit a late equaliser and there were plenty of positives to take from the game - including Matty James' comeback from injury.
A keenly-contested affair unfolded with United clearly not going through the motions despite already having the group title in the bag. Ajose was a constant threat with his pace and was twice almost played through in quick succession before opening the scoring after 18 minutes. Marnick Vermijl's forceful run took him past Steve Irwin and his cross was tucked home by the Bury loanee.
There was a scare for the visitors when Davide Petrucci diverted an Irwin cross towards Ben Amos, before Obertan forced a block out of Danny Wilson at the other end and then snatched at a chance following a fine one-two with Ajose.
Shelvey levelled matters for Liverpool when Cole touched a short free-kick into his path as the former Charlton midfielder's powerful drive flew past a motionless Amos.
Ajose almost restored United's lead when forcing Deale Chamberlain to beat the ball away and the youngster was unable to convert after the break from a brilliant move involving Oliver Norwood and Vermijl.
The impressive Shelvey chipped a decent attempt over the top but there was a let-off for the hosts when Joshua King burst clear and appeared to be held back by Wilson. The Norwegian still scrambled the ball past Chamberlain but the keeper recovered to pounce on the loose ball.