Dale were robbed of a third successive League draw after Colchester scored five minutes from time to steal all three points at Spotland.
Ian Henderson calmly chipped Josh Lillis with time running out to ruin Dale's undefeated start to the season.
Keith Hill's men started the game well and controlled possession, but Colchester found a way back into the game and went ahead in the 38th minute through a deflected effort from Andrew Bond.
The home side equalised two minutes into the second half through Craig Dawson from a corner and went on to dominate the first half of the second period.
However, with five minutes remaining in the game Henderson broke the Dale back line to chip 'keeper Lillis and take three points back down south.
Keith Hill made one change from the side that started at Brighton last week, with Anthony Elding, who had made a great impact from the bench in his last two games, coming in for Jean-Louis Akpa Akpro. Otherwise the team was the same, with Josh Lillis in goal and Scott Wiseman, Marcus Holness, Craig Dawson and Joe Widdowson making up the back four. Brian Barry-Murphy, Gary Jones and Jason Kennedy were in midfield, with Chris O'Grady, Joe Thompson and Elding up top. Former Dale favourite David Perkins was in the Colchester line-up, more than two years after his move south from Spotland.
Dale started the game well, keeping possession and probing a Colchester side that had picked up two draws in their opening matches. Unfortunately though it was possession without much penetration for the home side as Keith Hill's side went in search of their first three points of the season.
With Dale having the better of possession they would have hoped to turn it into at least one goal whilst they had control. Joe Thompson had a great chance to do just that, but he seemed to be caught in two minds ten yards out as he hit a tame effort with his left foot towards goal with Anthony Elding also in a good position.
Craig Dawson felt he had a good shout for a penalty just moments later when he was hauled to the ground from a corner kick, but referee Miller waved play on. Certainly the fans in the TDS Stand behind the goal felt Dale should have had a spot kick.
But despite Dale's possession in the opening half an hour they couldn't turn that into any form of lead, and this gave strength to Colchester who started to have good possession themselves and a few very good chances.
First David Mooney pealed away from Craig Dawson at the back post only to head over Ian Henderson's cross, before Henderson should have put his side ahead himself when he hit the crossbar.
A mistake from Jason Kennedy gifted the U's possession and a ball past Marcus Holness saw Henderson one-on-one with Josh Lillis, but the winger's chip had too much on it and hit the bar before being cleared.
Henderson again proved a thorn in the Dale defence when he hit a great shot from outside the area, but Lillis was equal to it and produced a fine fingertip save to deny Henderson a top corner strike.
However, there was nothing Lillis could do in the 38th minute when a deflected shot from Andrew Bond found the back of his net. Bond struck a shot from 25 yards out which hit Jason Kennedy before flying past a rooted Lillis in the Dale goal.
It was certainly a blow for Dale who had done well in keeping possession building up to that point, but now it was John Ward's side who were in control and they could have added to their score before half-time, again through Andrew Bond.
The midfielder had a left foot shot from outside the area which he mishit over the bar, before turning a corner goalwards on the stroke of half-time which Lillis was equal to.
Dale had started the half well and will have been disappointed to go into the break a goal down, but they will have been hoping to correct that early in the second half and that is exactly what they did.
Joe Widdowson won a corner which was taken by Brian Barry-Murphy and directed to last season's 11 goal hero Craig Dawson who directed a half volley past Mark Cousins in the Colchester goal to bring Dale level.
That goal seemed to inspire Dale and they began to concern the Colchester defence on numerous occasions. With little over ten minutes of the second half gone Keith Hill brought on Jean-Louis Akpa Akpro and new signing Andrew Tutte for Anthony Elding and Joe Thompson, with Akpa Akpro almost having an instant impact.
Craig Dawson picked the substitute out with a searching ball that he was able to bring down before turning his marker and firing a shot which cannoned off the crossbar and out of danger.
Keith Hill's side were definitely the better side in the second period and Akpa Akpro had given Dale renewed energy with introduction. He picked up a loose ball just outside the Colchester area and broke forward before firing a left foot shot wide of the right post.
The home side were having good possession a la the first half, but they couldn't find that elusive second goal. Chris O'Grady was having a fine game up top with his brute strength being a big factor in Dale being able to get the ball forward.
However, Colchester were always a threat coming forward on the counter attack, and with five minutes to go they stole the three points with a deadly break through Ian Henderson.
A ball was played forward to David Mooney who had time to bring it down, turn and run at the Dale defence. He found the run of Henderson who chipped the ball over the onrushing Josh Lillis to put the away side ahead with little time for another Dale equaliser.
This prompted Keith Hill to bring on Jack Redshaw for Jason Kennedy, but with the game about to enter added time Colchester almost made their win certain, but for Josh Lillis who made a fine one handed save to deny Lee Beevers a curling effort.
