First half display enough for home side.
Whilst the first team were battling against Coventry City, Richard Hall's young side took on City at the Cardiff City Stadium.
The home side had a experienced midfield of Jordan Mutch, Stephen McPhail and Filip Kiss and the trio played a big part in the 4-0 victory.
City found themselves ahead after just fourteen minutes, as Luke Coulson finished past Shaun Phillips from close range.
And a quickfire double extended that advantage and gave the home side a cushion which put the game beyond the U's.
First, Etien Velikonja lifted the ball over Phillips with a great touch, before the midfield duo of Mutch and McPhail combined with a neat interchange which saw the former Birmingham man tuck home.
Just before the break, the third of that midfield trio got on the scoresheet as Kiss put one past Phillips that clipped the post on its way to goal.
Having experienced a heavy defeat in their last game against Bristol City, the U's youngsters stood firm in the second half, though.
Freddie Ladapo found himself as the U's main dangerman in the second period and, although they did not get on the scoresheet themselves, the U's will take some heart from an improved second half display.