Despite a strong second half display, Colchester United were defeated for a third time in this year's Premier League Cup competition as Birmingham City took the points.
It means that City pick up their first points in this year's group stages, whilst the U's await their own, as the visitors showed a more ruthless edge in front of goal.
The U's were left to rue some misfortune in their own finishing, not least when Eoin McKeown hit the outside of the post after just ten minutes.
And that bad luck was compounded a minute later when Kyle McFarlane raced through to slot past Ethan Ross.
City were on the front foot and got their second on the half hour mark when Ryan Stirk finished a good move by twisting twelve yards out and finding a path to goal through Ross' legs.
The U's finished the half in a positive fashion, though, and continued that in the early moments of the second forty-five minutes.
Louis Dunne headed over when well placed on the hour mark, before a dangerous ball swung into the box evaded the outstretched legs of McKeown and Todd Miller nine minutes later.
The U's continued to press but their good work was undone with nine minutes to go when Anderson's low shot bent past Ross and found the far corner.
Ken Charles fired one just over on 85 minutes, before Dean Ager saw his shot go wide after a good run forward.
And Ager could have broken the U's duck in injury time after a fine U's move, but his shot rolled agonisingly wide.
And salt was rubbed into the wounds when McFarlane got his second and Birmingham's fourth with another tidy finish.
U's: Ross, Anderson, Clampin, Agboola, Cracknell, Chilvers (Ager 60), Dunne, Sims (Jones 60), McKeown (Charles 72), Miller