MK Dons boss Karl Robinson admitted his side could not have done much more to win the game after Colchester held out for a 0-0 draw.
The Dons found U's goalkeeper Sam Walker in inspired form as time and again he denied the hosts.
Robinson, forced to watch from the stands as he served a one-game touchline ban, could scarcely believe his side had not managed to take all three points from a match they dominated from start to finish.
"We have to take the positives out of it - there was a clean sheet and we created chances, but their goalkeeper - the save he made from Stephen Gleeson was the best I've seen for a long, long time," he said.
"A large part of our football was very, very good.
"They had one half-header but other than that, they didn't have a shot on goal.
"I know Joe (Dunne) and maybe after the respect that he's shown us, he's gone away with the point that they deserve.
"We were poor at their place but I thought that we played well and we moved the ball very quickly and very efficiently against a good Colchester side who will beat teams.
"The fans stuck with the team and everybody saw that we finished the game with 50 per cent of our home-grown players on the pitch.
"I dealt with not being in the dugout very, very badly - I think I changed seats about four times!
"It was horrible and I couldn't get involved with the game but I abided with the rules."
Walker made save after save during the clash, denying Patrick Bamford, Shaun Williams and Ben Reeves before the pick of the bunch, a fingertip save that diverted Stephen Gleeson's strike on to a post late on.