Jay Simpson opened the scoring with a tidy finish early in the first half for his first goal of the season.
Nicky Hunt struck the O’s second in the opening minutes of the second half, which then spurred a superb Simpson strike from long range to cap of the convincing victory for Orient, as they move up to 19th in the table.
Alberto Cavasin made seven changes to his that were hit for six in the FA Cup last weekend by Sheffield United. Whereas Colchester defender Luke Prosser was injured in the warm-up and was replaced by Frankie Kent.
Leyton Orient took the lead just 11 minutes in with the first real attack of the match, as the ball was not cleared by Colchester. A fortunate ricochet off the Colchester defender for Orient inside the box put Simpson in on goal to tuck it passed Sam Walker.
Orient were the more threatening, as a long ball was headed down by Simpson for former U’s winger Gavin Massey to hit on the volley but was well stopped by Walker.
Colchester were struggling to break Orient down, as Richard Brindley had a shot from 30 yards which went well wide of the target.
Massey burst down the left and into the box but his ball across goal could not be turned in by Simpson as it went all the way across the Colchester box.
The hosts pressed before the break for the equaliser, as Drey Wright’s shot was straight at Alex Cisak.
Brennan Dickenson for Colchester whipped in a dangerous ball in injury time to the far post but could not be turned in despite the home sides on rushing sliding efforts.
In the second half, Orient scored virtually from the restart after Collins’ endeavour to keep the ball in out wide was rewarded, as the ball fell to Hunt whose drive went low into the bottom corner.
The hosts had a glorious chance to get back into the game, as Dickenson cut the ball back across goal for Kurtis Guthrie to have a shot unmarked inside the box but dragged it wide.
Just after the hour mark, Dickenson was again dangerous down the left as he hit a fierce shot which stung the hands of Cisak but was cleared by the Orient defence.
Colchester possession dominance showed over Orient, as Tom Lapslie found some space on the edge of the box but his shot went over the bar.
Just when Colchester looked like getting back into the match, a long ball by Cisak was headed by Ollie Palmer into the path of Simpson who strike from 20 yards went straight into the top left corner, to secure the three points for Orient.
Orient were then playing with confidence, as Callum Kennedy clipped the ball into Palmer who headed the ball into the path of Massey whose volley was saved by Walker.
Captain Robbie Weir then got in on the action, as he drove in a shot from a broken down corner to lash his shot goalwards, which was tipped over the bar superbly by Walker.
Leyton Orient secured their fourth away victory of the season, as they jump ahead of Colchester and look to carry the confidence into their game at home against Blackpool next weekend.
Colchester United Lineup: 1Sam Walker, 2 Richard Brindley (68), 4 Tom Lapslie, Frankie Kent, 7 Drey Wright, 11 Brennan Dickenson, 14 Alex Wynter, 18 Tom Eastman, 19 Macauley Bonne, 28 Kurtis Guthrie (54), 32 Glen Kamara (54)
Substitutes: 25 Dillon Barnes, 10 Sammie Szmodics, 17 Denny Johnstone (54), 24 Craig Slater (54), 31 Tarique Fosu (68), 41 Louis Dunne
Leyton Orient Lineup: 1 Alex Cisak, 3 Callum Kennedy, 6 Tom Parkes, 7 Michael Collins, 8 Robbie Weir, 9 Ollie Palmer (90), 11 Gavin Massey (78), 15 Nigel Atangana, 16 Nicky Hunt, 27 Jay Simpson (84), 37 Yvan Erichot
Substitutes: 24 Sam Sargeant, 5 Alan Dunne, 10 Paul McCallum (84), 22 Sandro Semedo (78), 25 Aron Pollock, 26 Victor Adeboyejo (90), 32 Henry Ochieng