Late goals spark dramatic victory.
Report with help from Brian WallerU's: Williams, Keys, Partridge, Kensdale, Ferlisi, Fenn-Evans, Moore, Pollard, Ager, Clampin, Jones
Used sub Cosgrave and unused subs Mulryne, Boiling, Syrett and Howard
Two mins later and the U's had their noses in front for the first time as Ager's shot slipped through the keeper's hands to cap a dramatic victory.
The hosts then rallied superbly and were presented with a chance to equalise when Jones was floored in the box and Aaron Cosgrave coolly beat the keeper with the penalty after 84 minutes.
The U's pressed and Ryan Clampin saw two shots saved but, in a rare Forest attack, they led again, as sub Arvin Appiah took a shot which picked up a slight deflection, taking the ball into the far corner of the net.
A deflected cross ran to Jones, but he shot against the post. However, minutes later from an Ager free kick from near halfway, Julius Fenn-Evans who hooked his shot in on 53 mins to make it 1-1.
After the interval, the U's turned the screw and started to dominate the game.
The visitors had the best of the early play, but Colchester got more into the game towards half time, which saw Dean Ager test the keeper from 35 yards out and then had a shot blocked by the keeper's legs after he was set up by Callum Jones.
Things did not start too well for them, however, as they went behind after three minutes as Virgil Gomis converted a cross from the left.
They took on Nottingham Forest, who were the best of the bunch in the northern section last season and ran out 3-2 winners in dramatic fashion at Florence Park.
Colchester United U18s made it a perfect weekend on Saturday, as they matched the first team's winning result.