Town's U21s threw away a half-time lead, given to them by Tawanda Chirewa, and ended up on the wrong end of a 2-1 scoreline at Colchester United's Florence Park training ground on Friday afternoon.
The hosts had the first chance early on but Jayden Fevrier pulled his close-range effort just wide of the target. Soon after, Chirewa burst forward and hit a goalbound shot which was deflected wide for a corner.
As the half-hour mark approached, a weak clearance from Town's Woody Williamson fell to Ossama Ashley but his first-time snapshot failed to hit the target as the keeper retreated back towards his goal.
Town, in their red and black away kit, were starting to impose themselves on the game though and Harley Curtis failed to connect properly from close-range, with his effort failing to trouble trialist stopper Kacper Danielewicz.
On 36 the young Blues took a deserved lead when Matt Ward burst into the box and was clearly tripped by a U's defender. Chirewa stepped up confidently to find the bottom corner from the penalty spot.
Fevrier then shot straight at Williamson after being teed up by the vastly experienced John Akinde, before a lovely Town move saw Ward play Chirewa through, but his first time attempt to lift the bouncing ball over Danielewicz was just about gathered by the back-pedalling keeper.
Whatever former Town youth coach Richard Hall said to his Colchester side at half-time clearly had the desired effect though, as the U's looked like a different team after the break.
Akinde headed wide from six yards after a good cross from Samson Tovide, before Fevrier picked up a loose ball in the area but could only find the netting on the outside of the near post.
In a rare foray forward, Max Hudson's left-wing cross was guided towards the near post by Harley Curtis but Danielewicz saved relatively comfortably.
On the hour mark more good wide play from the home side saw Fevrier cross and the unmarked Tovide head wide at the back post.
Three minutes later, Akinde latched onto a good through ball and saw his strike come back off the foot of the post, moments before the Essex side deservedly equalised.
A long ball forward was flicked on and although centre-back Zak Bradshaw seemed to have the situation under control, a short back-pass allowed Ashley to nip in and slot the ball past the stranded Williamson.
On 68, John McGreal's side fell behind after another defensive lapse led to Cameron Stewart bringing down an attacker in the box, and Akinde stepped up to score the resultant spot-kick.
Town did keep going and created a couple of half-chances as the half wore on, but sub Gerrard Buabo's effort lacked power and was easily saved, before Chirewa drove forward and saw his shot from the edge of the box deflect inches wide with ten minutes remaining, although a side pass to the unmarked Zanda Siziba may have been the better option.
It was the proverbial game of two halves with Town on top for most of the first half, but Colchester dominating and looking dangerous for much of the second.
Curtis and Chirewa both caught the eye but former defender McGreal will undoubtedly be disappointed with the goals that his side gave away.
U21s: Williamson, Agbaje, Hudson, Alexander, Stewart, Bradshaw, Ward, Armin, Curtis (Buabo 59), Chirewa, Nwabueze (Siziba 59). Unused: Manly, Cullum, F Barbrook.