Harvey Knibbs, Sam Smith and Ben Worman all scored as United eased to victory, with Danny Rose' s late consolation one of few positives for Town. Here are our player ratings....
9. Dylan Connolly
Disappointing display on the wing. Made poor decisions, surrendered possession cheaply and seemed reluctant to use his pace and drive at Cambridge. Needs to do much better than this if he wants a regular place in the team... 4
10. Danny Rose
Not a lot happened for him at the top end of the pitch but he kept toiling away and got his reward with an excellent header... 6
11. Kion Etete
Cambridge were clearly fearful of his pace and he was all over them in the early exchanges, but the home defence dropped deeper than in the original tie and that helped to nullify his threat... 6
12. Aaron McGowan
As bright as anyone once he replaced Harriman shortly before half-time, regularly popping up in the final third. Provided the assist for Rose with a lovely cross... 7