Second half goals see off Town.Melaugh got the scoring underway, when he latched onto a through ball, rounded the keeper and rolled home.
The first half saw both teams struggle to really get to terms with a difficult pitch, but the U's did have the lion's share of the possession.
All the goals came in the second half, with Ryan Melaugh and Macauley Bonne each netting twice.
A young U's side have beaten Witham Town 4-1 to keep up the U's winning start to the season.
Three minutes later, another two substitutions were made, with Connor Clarke and Jack Curtis replacing Jack Simmons and Frankie Kent.
Hubble put a great through ball behind the Witham defence, with Melaugh timing his run perfectly to round the keeper and roll the ball into the empty net.
It didn't take the U's long to open the scoring in the second period, with only four minutes gone.
Sammy Szmodics came on in midfield, while Karl Duguid upped the average age of the side as he came on at left back.
Two changes were made at the break, with Alex Gilbey and triallist Craig Barrett given a rest after a tough forty five minute workout.
The first half finished the way it started, with striker Nwachuku shooting wide of the target.
Conor Hubble then put his shot from distance well over the bar, before Melaugh's effort from the edge of the box was deflected for a corner.
The first half chance for the home team came on twenty six minutes, as a long throw caused a bit of panic in the six yard box before Alex Gilbey cleared.
Ladapo turned provider on fifteen minutes, chesting down a cross for Ryan Melaugh. Unfortunately, Melaugh's volley flew over the crossbar.
Fellow striker Freddie Ladapo then followed suit, before being foiled by a bobble in front of goal with a subsequent chance that came his way.
Mason Spence showed great skill on three minutes, before crossing to Nnamdi Nwachuku who couldn't get his snapshot on target.
Last season saw the U21s squad physically outfought by their Essex non league neighbours but there was no repeat of that, with all the early pressure coming from the U's.
The original plan was for the senior lads to get another forty five minutes under their belt, but a great workout against Heybridge on Wednesday night gave the U's boss the chance to give the younger lads some match time.
With a lack of matches for the young U21s side, Joe Dunne gave the youngsters some valuable minutes to prepare them for the season ahead.
And with seconds left on the clock, he struck at the near post to make it four.
His first was a low drive across the face of the home keeper, who was fortunate still to be on the pitch.
After a Witham equaliser, he doubled his tally with a superb strike, before Bonne got himself onto the scoresheet.
Phillips then had to tip over a far post header, before the U's took control for the remainder of the game.
Unfortunately, the ball rebounded and was turned home from close range via the crossbar.
A low free kick looked goalbound but Shaun Phillips managed to get down and get a hand to it.
The home keeper then denied Szmodics with a great save with his legs, after a great one two got the U's young midfielder in behind the defence.
He was the victim of a horrific two footed tackle from the Witham keeper, who was extremely fortunate to stay on the pitch.
Subs: Duguid, Clarke, Szmodics, Curtis, Bonne, Olufemi, O'Donoghue
The win made it two in twenty four hours for the U's and they'll be looking for a hat-trick of victories at Sudbury on Friday night.
Substitute Michael O'Donoghue got down the left, crossed to the near post for Bonne to flick home to finish the scoring for the night.
And with a minute or two left on the clock, he doubled his tally with the U's fourth goal.
He was quickest to the ball on the corner of the box and drilled his shot low across the keeper and into the far corner.
Three minutes later, it was 3-1 as Bonne got his first of the night.