Town's play-off hopes were dealt a major blow after Colchester United defeated them 2-0 at Layer Road. The Blues dominated for the most part, but looked little threat in front of goal, while Scott Vernon netted two of the home side's chances, one in each half.
Jim Magilton stuck with the side which drew 0-0 with QPR a week ago with Shefki Kuqi and David Norris remaining on the sidelines due to hamstring and ankle injuries respectively. Pablo Couñago served the second game of his three-match ban and was sat amongst the Town supporters in the Tiptree Stand.
The Blues started strongly and won a series of corners, the game's first chance falling to Gavin Williams, but the Welshman shot across the face of goal from the edge of the area.
Sito was yellow-carded for a foul on Johnnie Jackson on 14, Karl Duguid sending the freekick well over Stephen Bywater's crossbar.
Three minutes later, Kevin Lisbie headed over the bar from a Dean Hammond freekick. After Town's strong start, the U's were beginning to come more into it.
As at Portman Road earlier in the season, they were making it hard for the Blues to play their natural game by quickly closing down the player with the ball. Town were also getting little from referee Andy D'Urso, the Essex-based official perhaps a surprise appointment for a game involving an Essex club.
Bruce saw a shot blocked on 20 after Dean Gerken had flapped at a corner, then for the home side Lisbie headed wide at the far post when it looked like he ought to have done better, although there was a suspicion of offside.
Alan Lee headed an Owen Garvan corner straight at Gerken on 24, then the Colchester keeper pulled off another save from the Irishman as the Blues got back in the ascendancy.
On 27 Velice Sumulikoski spurned another good chance when he headed into the keeper's arms from a Sito cross which had been nodded on by Lee.
Two minutes later, the U's went in front with what was their first serious shot on goal. Lisbie looked to have messed up his chance of a goal when he misdirected his first touch on a long ball away from goal. But the former Charlton man held the ball up and deftly played in Scott Vernon, who had little trouble in beating the advancing Bywater.
Town went looking for the equaliser but on 33 Lee's low cross was too far in front of Gavin Williams.
Lee missed a golden opportunity to put the Blues back on terms in the 37th minute when he seized on Matt Heath's error on the edge of the area. The Town frontman was allowed a clear shot on goal but scraped the ball wide when he really ought to have scored.
Simpson cut in from the right and had a shot blocked, then Quinn's volley from the edge of the area was headed in by an offside Danny Haynes, the linesman's flag curtailing Town celebrations.
The Blues probably deserved to be on terms at least at the break. They had enjoyed most of the possession and had created a number of good chances. Crucially though, all had been wasted, while Scott Vernon had netted one of the home side's few opportunities.
Half-time saw a spontaneous if hardly widespread protest against Colchester's new ticket prices with fans chanting "£26, you're having a laughâ€Â. The new pricing was released too late for supporters to co-ordinate a proper protest this weekend with more organised demonstrations planned for future matches.
Alan Lee felt he ought have been awarded a penalty seven minutes into the second period short appeared to be pulled by both Heath and John White, but referee Andy D'Urso waved away the protests. Spotkicks have been awarded for an awful lot less.
The Blues had started the second 45 minutes strongly and on 55 Quinn shot wide. Two minutes later the former Sheffield United man was perhaps surprisingly subbed for Gary Roberts, last week's boo-boy making his way on to the field to applause and cheers.
Simpson saw a shot blocked inside the six-yard box but the whistle had already gone for a handball by Danny Haynes, prior to the former England U19 international making a strong run in from the right and cutting the ball back to Alan Lee. The Irish striker failed to get in a decent shot and the opportunity was gone.
Johnnie Jackson shot wide for the U's, before Jordan Rhodes took over from Velice Sumulikoski. The youngster took up his usual striking role with Haynes moving to right midfield and Gavin Williams into the centre.
Alex Bruce headed Gavin Williams's 64th minute freekick narrowly over the bar, then the U's scored again. Sito failed to deal with a long ball over the top, merely managing to divert the ball into Vernon's path, the striker again having little problem in beating Bywater in the Town goal.
With Town so poor in front of goal all afternoon, two goals in the remaining minutes looked an impossibility. Gary Roberts's 76th minute freekick â€" which looped miles over Gerken's goal â€" just about summed up the entire afternoon.
Colchester continued to defend stoutly, blocking a Haynes shot before Tommy Miller replaced Gavin Williams. The Welshman had looked somewhere nearer his usual self than he did against QPR but still some way from his best.
Jordan Rhodes came close to netting his first senior goal for the Blues with a shot on the turn which Gerken did well to save. The home side almost added a third when Lisbie broke quickly but fired over the bar.
Stephen Bywater made a mess of a clearance on the left touchline with two minutes left, Lisbie taking a shot from a tight angle and Alex Bruce heading from under his own crossbar.
The on-loan keeper did somewhat better moments later when got across to his left to save Phil Ifil's 25-yard strike.
Town continued to push, although a number of heads had appeared to drop after the second goal went in. As the game drew to a close, Sito walloped a freekick and its rebound into the wall, then Gerken saved another set piece from Garvan.
A dismal afternoon from Town, who remain in seventh a point behind sixth-placed Wolves, who have a game in hand. Perhaps as significantly, the Blues are now starting to lose touch with the top five and sixth now looks to be Town's only hope of a play-off place.
Jim Magilton's men had most of the ball throughout, but for all their possession failed to give Dean Gerken a particularly difficult afternoon. All too often good situations were wasted due to poor crosses and when decent chances were created, all too often the finishing was woeful. Not too much different from the situation a year or so ago when the Blues found it similarly difficult to score a goal.
Perhaps inevitably, Colchester were somewhat less profligate when their chances came on the break, Scott Vernon showing the kind of clinical finishing which would have secured the Blues points not just this week, but last week and on several other occasions this season.
Victories over Cardiff and Norwich over the next week look essential if Town's game at Wolves on April 19th is going to be as crucial as it currently appears.
Town: Bywater, Simpson, Sito, De Vos, Bruce, Garvan, Sumulikoski (Rhodes 62), Quinn (Roberts 57), Williams (Miller 85), Haynes, Lee. Unused: Colgan, Wright. Att: 6,264.