Two devastating second-half strikes from Harry Anderson and substitute Jack Payne in six minutes either side of the hour halted the Exiles’ League Two revival at Rodney Parade.
County had lifted out of the relegation zone last Tuesday after a rip-roaring 3-1 victory over free-falling Tranmere at NP19, but now slipped back into the bottom two following this latest reverse and fellow strugglers Barrow picking up a crucial point from a draw at Cheltenham on Friday night.
Yet, the Port, who slipped to a 22nd league defeat of the season, will be fuming over referee Stephen Copeland allowing Anderson’s opener on 58 minutes to stand, though midfielder Matt Smith appeared to be clearly impeded in the build-up to the goal.
Payne netted the U’s second, which rubbed more salt into the gaping wound. County sub Lee Jenkins’ reply deep into added time, a superb diving header, was no more than a scant consolation.
The Port are still effectively only a solitary point from safety, though 22nd-placed Barrow have played two games fewer and hold a plus-10 superior goal difference. Just above the Cumbrians are Crawley on 29 points.
Colchester, who lost young borrowed Charlton raider Micah Mbick to a serious-looking ankle injury on 36 minutes, boosted their play-off hopes with this hard-earned win which might have been more emphatic if they had taken maximum advantage of Newport’s rather tentative performance, particularly in the opening 35 minutes.
County reshuffled their midfield pack, drafting in former Wales international Smith and the attacking guile of Ged Garner, which provided additional flexibility because of the inclusion of Cameroon flyer Bobby Kamwa as support to central attacking warhead Courtney Baker-Richardson.
The U’s were seeking to reignite their dimming play-off ambition, boss Danny Cowley making a quartet of alterations to the team hammered 3-0 in midweek at Chesterfield. Ex-Burton defender Tom Flanagan skippered the side from a back four that also featured Frankie Terry at left-back. Mbick partnered Sam Tovide up top, with on-loan Ipswich player Finley Barbrook anchoring central midfield.
Referee Copeland delayed the start of the clash by five minutes to rectify a problem with goal netting at the South Stand end. Colchester were soon seeking the early breakthrough, however, Mbick rising high to nod over at the near post after Terry had escaped on the right in the fourth minute.
Bishop and Barbrook were dominating midfield and from this platform the U’s were able to apply crippling pressure on a Port defence that was holding firm, captain Matt Baker and Ryan Delaney doing their utmost to snuff out the menace.
Exiles keeper Jordan Wright looked on anxiously as Mbick glanced another opportunity wide before the ex-Grimsby custodian sprang low to his left, grasping a Kyreece Lisbie drive, then pawing clear from Kane Vincent-Young as Colchester wallowed in a glut of possession.
Yet disaster befell lively Mbick just before the half-hour, the raider slumping awkwardly after a solid Cameron Evans challenge. The youngster was stretchered off after an enforced interlude, being replaced by Payne.
The moment had clearly shaken the U’s and County moved forward within the 14 minutes of additional time. Baker glanced a Kamwa corner inches past an upright, while a Tom Davies rocket then screeched wide as the Port finally displayed their teeth.
Match statistics showed Colchester had registered over 60% possession and notable dominance in the County box. One sharp raid saw Samson Tovide clip the Port bar with a flick from a Lisbie feed, the prelude to what was to follow.
Linkman Smith appeared to be impeded, but official Copeland allowed Anderson to advance and bag Colchester’s 59th-minute opener, the ex-Lincoln schemer’s raking 18-yard effort evading Wright’s left hand.
The contest appeared settled five minutes later. Lisbie’s feet weaved the opening on the left of the area, Wright did beat back Tovide’s effort, only for Payne to nod into the empty net.
County altered strategy, going with three centre-backs and five in midfield. Lee Jenkins, Harrison Biggins, Ben Lloyd and striker Nathan Opoku were all in the fray by 70 minutes. Yet, despite an abundance of late pressure, Colchester were moving toward their 14th league win of the season.
Kamwa struck the inside of a post near the death and, despite Jenkins pulling a goal back in the sixth minute of added time for the rallying County, in truth this encounter had drifted away long before.
Newport County (4-1-3-2)
Jordan Wright
Cameron Evans
Matt Baker (C)
Ryan Delaney
Tom Davies
Sven Sprangler
Matt Smith
Michael Spellman
Ged Garner
Courtney Baker-Richardson
Bobby Kamwa
Subs
Shaun MacDonald (GK)
Harrison Biggins for Smith 69 mins
Lee Jenkins for Davies 69 mins
Ben Lloyd for Garner 56 mins
Lewis Jamieson
Nathan Opoku for Spellman 69 mins
Cole Jarvis for Evans 90 mins
Colchester United (4-4-2)
Matt Macey
Kane Vincent-Young
Tom Flanagan (C)
Jack Tucker
Frankie Terry
Kyreece Lisbie
Finley Barbrook
Teddy Bishop
Harry Anderson
Micah Mbick
Samson Tovide
Subs
Rob Hunt
Jack Payne for Mbick 35 mins
John-Kymani Gordon for Anderson 89 mins
Arthur Read for Bishop 74 mins
Jaden Williams for Lisbie 89 mins
Will Goodwin for Tovide 89 mins
Romeo Akachukwu
Referee: Steven Copeland
Assistants: Jack Clench and James Hooper
Fourth Official: Andrew Ellis
Attendance: 4,328 (302 away)