The Owls' record of never having won at Layer Road continued as in-form Colchester earned their fourth consecutive home win. Jamie Cureton's first-half strike, and further goals from Greg Halford, Chris Iwelumo and Karl Duguid, consigned the club to their heaviest defeat of the season.
Wednesday's preparations for the game had been disrupted by news of Chris Brunt's illness and Glenn whelan's failure to pass a late fitness test. However, Graham Coughlan was deemed fit to play, with Burton O'Brien coming in and Lee Bullen and Marcus Tudgay given the nod to add an aerial presence.
Paul Sturrock had briefed his charges to expect an up-and-at-'em approach from the hosts and giant frontman Iwelumo was heavily involved early on. But the U's presented an even greater threat from players running behind the Owls defence and, after 49 seconds, the visitors relied on keeper Brad Jones to thwart Richard Garcia's low shot from just such a run.
The hosts often looked to attack down their right flank, and Madjid Bougherra and Frank Simek were both forced to deal with dangerous low crosses from that side before Colchester finally took the lead in the 28th minute. Right-back Halford launched a hopeful ball towards the penalty area but Bougherra made the fatal mistake of allowing it to bounce and Cureton nipped between the Algerian and Jones to lob his 150th league goal into the empty net.
It had by no means been one-way traffic, with Steven MacLean's long-range free-kick held by keeper Aidan Davison at the third attempt, and Yoann Folly and Simek shooting over. But manager of the month Geraint Williams would have felt his team was good value for its half-time lead.
Within a minute of the restart the Owls could have been two down - in almost a carbon-copy of the first. Again, Cureton latched onto a bobbling ball to lob over Jones, but this time Bougherra managed to race back and hook his shot off the goal line. In the melee that ensued, Duguid shot just wide.
Wednesday had clearly been given interval instructions to get the ball wide and send crosses in, and they nearly profited from this tactic after 50 minutes. Davison made a hash of O'Brien's skidding cross but, under pressure from Tudgay, managed to smuggle the ball away for a corner. Then, after another scramble originating from John Hills' dart into the box, Steven MacLean missed a gilt-edged opportunity. Tudgay's mishit shot left the Scot with just the keeper to beat from six yards but he skied his left-footer over the bar.
That miss was compounded after 56 minutes by one of the best goals scored against the Owls in years. Million pound-rated Halford found space, around 35 yards out, and sent an absolute screamer past Jones and in off the far post.
It got worse, five minutes later, when Iwelumo latched onto Garcia's pass and drilled a low shot past Jones' outstretched right glove.
Sturrock made a triple substitution, sending on Deon Burton, Drew Talbot and Kenny Lunt in place of Bullen, MacLean and Tudgay. But as the Owls poured forward, Pat Baldwin and Iwelumo both saw headers saved by Jones.
Bougherra ended a weaving run by firing over, Burton shot wide on the turn, and Talbot appeared to be felled by Davison as he was making space to shoot. But the fourth from Duguid set the seal on another miserable trip to Essex for the Owls, who now have to regroup for Saturday's meeting with QPR.
Colchester (4-4-2): Davison; Halford (White 88), Brown, Baldwin, Barker; Garcia (McLeod 73), Izzet, Watson, Duguid; Iwelumo, Cureton (Guy 81). Subs: Gerken, Jackson.
Wednesday (4-4-2): Jones; Simek, Bougherra, Coughlan, Hills; Bullen (Lunt 63), Folly, O'Brien, Small; Tudgay (Talbot 63), MacLean (Burton 63). Subs: Adamson, Spurr.
Attendance: 5,097
Referee: Richard Beeby
Booked: Simek (foul) 19 mins, Garcia (foul) 59 mins, Bougherra (dissent) 90+3 mins
