Town's U18s were well-beaten 4-1 by Isthmian League North Division side Brightlingsea Regent at North Road in a pre-season friendly on Saturday afternoon.
Blues keeper Will Fletcher produced two fine saves early on, firstly to get fingertips on a cross-shot and then to get behind a thunderous long-range shot from Charlie Durling.
The young Blues fell behind on 32 though when Callum Harrison's right-sided free-kick was met at the back post by Josh Chapman, who looped his header over Fletcher and into the net.
A minute before the break, one-time Town schoolboy Fin Adams doubled the home side's lead with a clinical header at the back post as he connected with a cross from the right.
On 52 the Essex side added a third when one of five trialists in the Town starting line-up fouled a Regent attacker in the box and Harrison stepped up to fire the ball into the top corner.
Just three minutes later and it looked like being a difficult second-half for Town when Shane Temple netted the fourth after reaching a low ball in from the right.
Although a raft of substitutions disrupted the flow somewhat, in fairness Town's teenagers dug deep and kept going throughout, restricting the home side to few other clear-cut chances.
And the Blues pulled a goal back late on when former Arsenal wideman Jayden Adetiba cut in from the left and hit a low shot which beat Regent's sub keeper at his near post.
The U18s, who beat Stevenage 2-0 in their first pre-season match last weekend, very nearly scored again moments later when Roman Burton-Yurevich released Adetiba again, but the keeper was out well to block his effort.
Burton-Yurevich then forced the stopper into a fine diving save to keep an effort out that was destined for the top corner, shortly before the referee blew for full-time.
Meanwhile, the U21s beat a Slovan Bratislava side 1-0 in the second friendly of their Slovakia training camp on Friday evening.
U18s: Fletcher (Bentley 62), Brouwers (Brown 46), O'Sullivan (Olawole 73), Trialist, Trialist, Sains (Longwe 46), Trialist (Adetiba 62), Trialist (Pedder 62), Eze (Burton-Yurevich 73), Nicolaou (Boakye-King 46), Trialist (Enkotosia 73). Att: 350.