In the opening 60 seconds, Colchester captain Karl Duguid collided with Preston keeper Carlo Nash at the keeper's right-hand post and had to be substituted by Johnnie Jackson.
David Nugent saw his 12-yard left-foot shot go straight to the Colchester keeper from Paul McKenna's left-wing cross and, after 20 minutes, Danny Pugh fed the ball to Daniele Dichio but, although the veteran striker's left-foot shot found the net, his effort was ruled out for offside.
Nugent scored the only goal of the game after 33 minutes when Matt Hill's left-wing cross was headed down by Dichio and the former Bury striker hit a ten-yard right-foot shot into the keeper's bottom right-hand corner of the net as he registered his sixth goal of the season.
Simon Whaley shot well wide and over the bar before Nugent was booked on the stroke of half-time for a foul on Colchester centre-back Pat Baldwin.
The U's replaced last season's top scorer Chris Iwelumo with 19-year-old striker Jamie Guy after half-time.
Colchester right-back Greg Halford had a 25-yard right-foot free-kick which flew wide and over and Jamie Cureton had a header saved by Preston keeper Carlo Nash.
The in-form Nugent then laid the ball into Dichio's path but his 15-yard right-foot shot was comfortably saved.
Colchester substituted Kemal Izzet for 18-year-old striker Hogan Ephraim after 72 minutes but it was Preston that maintained the initiative as Nugent raced down the left-hand side and cut inside before having his shot saved.
Dichio was replaced by Tommy Miller, who is currently on loan at Deepdale from Sunderland, and substitute Guy was booked for a foul on Hill.
A minute later Preston captain Graham Alexander was booked for a foul on substitute Ephraim. Lewis Neal replaced Simon Whaley and Chris Sedgwick had a left-foot shot saved by Dean Gerken.
Nugent limped off and was replaced by Kelvin Wilson as Preston finished the game with no strikers.