A mistake by Colchester United's rookie defender Daniel Steele handed three points to visiting Brentford.
Former Millwall teenager Steele, who came on as a 42nd minute substitute for the injured Mark Warren, conceded a penalty in first-half stoppage time when tussling with Mark McCammon just inside the penalty area.
It was the linesman who gave the penalty and Steve Hunt stepped up to crash home the spot-kick high to Richard McKinney's right.
The 1-0 half-time deficit was a little cruel on Colchester who had dominated in the early stages with teenage striker Dean Morgan unlucky on a couple of occasions.
Morgan had an early header which looped over the bar, and had a curling free-kick fingertipped away by Brentford keeper Paul Smith.
Yet the Londoners who are unbeaten this season with three wins and a draw, were in control for most of the second half and McCammon had a goal disallowed on the hour mark when he was adjudged to have fouled McKinney.
McKinney kept his side in the game when pulling off a terrific save to beat away a header from Leo Roget. Man-of-the-match Rowan Vine struck a shot from the edge of the box into the side netting as the Bees finished the stronger.
Colchester, after an opening day win against Stockport, have now mustered just one point from their last three games.
Manager Steve Whitton produced a shock before the game when dropping Scott McLeish, last season's leading scorer, from the team and in fact the squad of 16.
Whitton said: "Scott was disappointed not to be in the squad but it's up to him to bounce back when he gets the chance.
"I didn't think we played that badly as a team, although at present our strikers are a little low on confidence," added Whitton.
HASH(0x92b2f40)