League One table toppers Charlton suffered their first home defeat of the season at the hands of Colchester.
Anthony Wordsworth's curling effort from 25 yards put the visitors ahead.
Bradley Wright-Phillips and Johnnie Jackson both went close to scoring an equaliser for the Addicks, while Ben Hamer denied Steven Gillespie.
But the Addicks keeper dallied and allowed Gillespie to charge down a clearance and divert the ball into the net to wrap the game up.
VIEWS FROM THE DRESSING ROOM.
Colchester United manager John Ward told BBC Essex:
"There can't be any short measures coming here. I think they are champions elect.
"They've got very good players in all departments, so if one of mine slips or doesn't put the shift in then we'd get punished.
"But that didn't happen. We did put a shift in all across the team. Every man has put the effort in and got us a fantastic result."