Penalty shoot-out drama sees them through.
The visitors started in expected lively fashion, pressing hard to put the U’s out of their stride.
As the match went to a dramatic penalty shoot-out, it was the U's who held their nerve to edge through 7-6.
The two teams traded chances after the interval, and Town finished the stronger with a series of chances just before the final whistle.
The home side had raced into a two goal lead, only to be pegged back just before half time with a quickfire double.
The U's made progress in the Essex Senior Cup in dramatic fashion on Tuesday night, winning a penalty shoot out against Billericay Town.
They should probably have had their noses in front early on, when Halle got up in a good position from a left sided free kick, but planted his header over the bar.
Billericay were moving the ball well, and using their physicality well against a younger U’s side.
However, the U’s got their noses in front on 15 minutes, somewhat against the run of play. Nwachuku broke through from midfield and passed to Szmodics on the edge of the box.
He initially appeared to have lost his footing, but he got up to fire one home into the far side netting beyond Lumley.
The goal settled the U’s down and they doubled their advantage midway through the first half. Freddie Ladapo won a corner and, when it wasn’t fully cleared, Nwachuku swivelled to slam home the home side’s second.
The visitors got one back on 33 minutes as good work from Junior Luke down the right saw him square it to Joe Benjamin in the area, and his tidy finish across Mark Cousins found the bottom corner.
The U’s almost restored their advantage straight away. Szmodics sent O’Donoghue away down the left with a fine ball, and he squared it to Nwachuku. He hit it first time and forced a fine save out of Lumley.
A minute later and the visitors were level. The ball was looped into the area from a set piece and Halle got up highest to bury a fine header past Cousins.
The U’s rode the storm after those two goals and nearly got in front just before half time, as good work from Vose set up Hubble, who forced a decent save out of Lumley.
At the start of the second half, it was Billericay who again started the stronger and a mistake from Sanderson saw Benjamin and Cousins come together, but the referee said no foul, before Sanderson swept up from his earlier error.
Vose was first to go close for the U’s in the second half, picking up a ball from Hubble and bending in a shot that went just wide.
Szmodics and Ladapo both put shots down Lumley’s throat, before Lapslie and Kent came on for Hubble and Simmons respectively.
Both teams could have got their noses in front with fifteen remaining. First Sappleton should have done better with a close range header, before Spence dragged a shot wide when well placed in the area.
The visitors then had two great chances. First the U’s lost the ball in a good area but Benjamin couldn’t beat Cousins. Then from a cross from the right, Sappleton headed just wide of goal.
Town were finishing the stronger, and Sappleton had yet another chance to score when he was given time to set himself on the edge of the box, shooting just wide of Cousins’ far post.
Bonnett-Johnson then fired one wide as the clock ran to its conclusion, but the visitors couldn’t get the goal they looked like they might find.
And so it went to penalties, as the U's made their way through.
Col U, Spence: Missed
Billericay, Sappleton: Scored
Col U, Sanderson: Scored
Billericay, Halle: Scored
Col U, Nwachuku: Scored
Billericay, Poole: Scored
Col U, Ladapo: Scored
Billericay, Collis: Scored
Col U, Vose: Scored
Billericay, Bonnett-Johnson: Missed
Col U, Lapslie: Scored
Billericay, Lumley: Scored
Col U, Olufemi: Scored
Billericay, Rogers: Scored
Col U, Kent: Scored
Billericay, Benjamin: Missed