An own-goal of horrendous proportions brought an ignominious end to Colchester's hopes of any giant-killing heroics as Blackburn took full advantage to register a comfortable victory in the FA Cup fourth round.

Aidan Davison, Colchester's much-travelled goalkeeper, was the culprit. As the 36-year-old tried to clear Kevin Watson's back-pass, he produced the sort of air-shot which will give him nightmares - and the ball trickled into the net after brushing his ankle.

The goal will last long in the memory - it is sure to become a firm favourite of 'FA Cup cock-up' videos - and completely deflated the Coca-Cola League One side, allowing Barclays Premiership Blackburn to run away with the game.

Jemal Johnson, the 20-year-old American-born striker who moved to Rovers' academy from Manchester United, scored his first senior goal on his first start - before Dominic Matteo ended the contest.

It was a shame for Phil Parkinson's visitors who had looked enterprising before that and had given the pathetic crowd of 10,634 an indication of how they beat Walsall 5-0 in midweek.

They showed plenty of attacking endeavour but were defensively naive - probably why they are so inconsistent in the league - and Robbie Savage's midfield dominance was barely challenged.

Blackburn pressed Colchester back from the opening whistle, and Johnson played in an inviting cross from the left only for David Thompson to make no contact at the back post.

Savage then came within a foot of putting Rovers in front with a curling free-kick from 25 yards, the ball bouncing past the post with Davison rooted to the spot.

But it was not all Blackburn, and Gavin Johnson showed Colchester's goal threat with a smart shot from the left of the area which forced Brad Friedel into a good save.

Andy Todd make an important block when Gareth Williams was the next visitor to try to embarrass the hosts - before Thompson led a Blackburn breakaway and set up Brett Emerton for a 20-yard shot which was easily fielded by Davison.

After 21 minutes, Blackburn took the lead through that freakish own goal - and it was harsh on Colchester who had shown plenty of promise.

Six minutes later Johnson made it 2-0.

Thompson found space down the right and picked out Morten Gamst Pedersen, and the Norwegian - either by luck or by great skill - span the ball off to Johnson who buried it past Davison from 12 yards out.

Todd was again in action to block Williams' shot. But Blackburn looked dangerous on the break, and Emerton picked out Thompson who struck a fierce drive which was well-smothered by Davison.

The match was put beyond Colchester's reach six minutes into the second half when Matteo scored his first goal for Blackburn to make it 3-0.

Savage swung in a free-kick, and Matteo made contact at the near post to steer the ball past Davison. That was the signal for Mark Hughes to bring off Aaron Mokoena to protect him from a possible red card, and New Zealand captain Ryan Nelsen came on in his place.

Pedersen nearly made it four after a classy through-ball by Johnson, but Davison tipped his effort around the post.

Emerton came close to a scoring a classic after a sinuous run but was a couple of feet wide; then two minutes later the Australian repeated his run and was on target this time - but Davison was able to parry.

The visitors had a glimmer of hope after a loose back pass by Todd gave substitute Guylain Ndumbu-Nsungu a sight of goal - but Nelsen came snapping in to block.

Colchester's Johnson had a decent chance for a clear shot but repeated Davison's trick and missed the ball completely.

Steven Reid came off the bench for Blackburn and nearly had an impact with a 20-yard strike which rocketed past the post.

Thompson struck the bar from Savage's cross; then substitute Jonathan Stead, desperately searching for his first goal of the season, had a go from 18 yards but was crowded out.

Nelsen did head the ball into the net from Savage's corner but was hauled up for a push.

Ndumbu-Nsungu could have had a consolation - but Friedel, one on one, made an excellent save with his legs.

Teams

Blackburn Friedel, Neill, Todd, Mokoena (Nelsen 52), Matteo, Emerton (Reid 71), Savage, Thompson, Tugay, Pedersen (Stead 71), Johnson.

Subs Not Used: Enckelman, Gallagher.

Booked: Mokoena.

Goals: Watson 21 og, Johnson 27, Matteo 51.

Colchester Davison, Stockley, Baldwin, Brown, Hunt (Chilvers 55), Halford, Danns, Watson, Johnson (Keith 79), Fagan, Williams (Ndumbu-Nsungu 58).

Subs Not Used: Gerken, Cade.

Att: 10,634

Ref: H Webb (S Yorkshire).