Padraig Amond was again the match-winner at Rodney Parade, as his second-half strike saw off Grimsby Town 1-0.
In truth, it could have been even more had it not been for a fine display of goalkeeping from away keeper James McKeown.
McKeown, who has been with the Mariners since 2011, did expertly well to deny the County goal scorer twice in the first-half, with O’Brien and Labadie also being denied in the opening 45 minutes.
But County finally found a way past McKeown on 63 minutes, as Amond got his third goal in County colours.
It was the result of an inviting delivery from Ben Tozer, with Amond reacting quicker than his marker to stab home from around eight yards after away defender Paul Dixon failed to clear the cross.
It was the second home game in a row that Amond had decided with an instinctive finish, as County extended their unbeaten home record at Rodney Parade.
Mike Flynn elected to make four changes from the side that lost 2-1 to Morecambe last weekend. That saw two changes in defence, with the other two coming in midfield.
Mark O’Brien, who had missed the last two games with a foot injury, returned in place of Scot Bennett, with Robbie Willmott replacing Dan Butler in the other defensive change.
Captain Joss Labadie recovered from his groin injury to replace Matty Dolan in central-midfield, with Sean Rigg coming in for Tom Owen-Evans in the final change.
The like-for-like changes saw the Exiles revert to a 4-3-3 system, with Frank Nouble and Robbie Willmott providing assistance on the wings for sole striker Padraig Amond.
Grimsby Town manager Russell Slade made the solitary one change to his side that beat Yeovil Town– with a familiar name to County fans returning to their starting side. Mitch Rose, who was on loan with the Exiles last season, came back into the midfield in place of Luke Summerfield.
That meant the visitors kept to the same formation as last weekend – as they appeared to set up in a 4-4-2 system.
And the visitors were the side to create the opening opportunity of the game. Within 60 seconds, the ball fell to Siriki Dembele in the County area, but the winger couldn’t quite connect to it and O’Brien was there to clear.
A potential head injury to Labadie gave County a scare on five minutes, but after a quick assessment, the captain was cleared to return to the game.
And not long after that, the Exiles created their first chance. Frank Nouble did well to drive into the area and find Rigg, whose cross looked destined to be tapped-in by Willmott, only for Paul Dixon to get the faintest of touches and turn it round the post.
The resulting corner saw Rigg unmarked at the far post, who could only fire wide, with Sam Jones hitting the side netting for the visitors with a free header on 10 minutes.
Nouble was at his mesmerising best in the initial stages, causing havoc to both full-backs in the opening quarter-of-an-hour, unlucky to not find Amond with crosses on two occasions.
The first delivery was collected superbly by visiting goalkeeper James McKeown, with the second one just clipping the top of Amond’s head and drifting wide.
County were well in the ascendency at this point, and McKeown had to produce a double-save to stop the Exiles from taking the lead. A corner from Rigg found O’Brien at the far post, only for McKeown to save with his legs, before he held Tozer’s attempt with the follow-up.
McKeown was looking sharp in the away goal, and had to rush off his line to prevent Nouble from getting in on goal, but could do nothing moments later to prevent Amond from having a shot, with the striker unlucky to see it just creep wide.
The away side were always looking dangerous on the counter-attack, but again had to turn to McKeown to keep them level, this time denying Labadie from all of four yards on 23 minutes.
The half-hour mark came and went without the visitors testing Joe Day in the Exiles goal, striker Jamille Matt failing to connect to a cross that may have forced a save from the home goalkeeper.
And the visitors were nearly made to pay for their somewhat slow start, as a high ball caused McKeown his first real issue of the game, only for defender Ben Davies to hook the ball off the line from an Amond header.
It would be unjust to say that County didn’t deserve a lead by this point, and McKeown had to be alive again to hold a Willmott free-kick, with Labadie waiting to pounce in the centre.
Day made his first save on 38 minutes, a routine one to hold a tame Matt header, as the visitors just let the Exiles know that they could expect to be punished for further missed opportunities.
O’Brien forced another save from McKeown as the game approached added time, White forcing another save from the goalkeeper at the start of two minutes indicated.
And if it wasn’t for another goal-line clearance from Davies, the Exiles would have been in-front. Demetriou rose highest from a corner and it looked like McKeown might finally be beaten, only for Davies to get something in the way of it.
That brought an end to a first-half completely dominated by County, and if it wasn’t for an inspired performance from McKeown, could have been a few goals ahead.
The visitors did look menacing on the break, Siriki Dembele looking like he could cause the defence some problems when he got going, with Day only having to make one save in the first-half.
It was clear that Slade had been frustrated by his sides efforts during the first-half, making a change during the break, Luke Summerfield coming on to replace Rose in the midfield.
But not even the change in personnel could prevent the Exiles from starting brightly again, Willmott unlucky twice in the opening five minutes to have crosses deflected behind.
An error from Ben White afforded the visitors their first real sight at goal on 52 minutes, Day holding the 20-yard effort from Matt with ease.
An intricate move spanning around 15 passes almost gave County their own sight at goal on 57 minutes, Summerfield intercepting the final pass with what was his first involvement since coming off the bench.
County could have been punished for missed opportunities on the hour as Matt had the ball in the back-of-the-net after a swift counter-attack, only for the Exiles to be reprieved by the linesman’s flag.
Pipe had to be alert to thwart Matt seconds later, as it looked like the visitors were gradually beginning to grow into the game, but the visitors couldn’t do anything to prevent Amond from finally giving County a deserved lead.
On 63 minutes, Tozer sent an inviting throw-in into the area which Dixon couldn’t clear, with Amond beating his marker to stab it home from just outside the six-yard area.
Interestingly, that was the first goal scored in a league game in South Wales between the two sides since 1979, after the previous three meetings had all ended goalless.
It took until the 68th minute for the game’s first yellow card to be awarded by referee Antony Coggins, away captain Nathan Clarke the offender, for re-entering the play after an injury absence before being told to by Coggins.
Slade threw on another substitution just after that incident, Dembele making way for Diallang Jaiyesimi.
And the substitute almost had the desired effect that Slade would have been looking for, with the winger forcing Day into a good save from just inside the area after driving past Pipe and O’Brien quite comfortably.
Willmott fired well over the crossbar as the game approached the final 15 minutes, JJ Hooper coming on for the final change for the visitors, this time Martin Woolford being replaced.
Summerfield almost grabbed an equaliser on 80 minutes, Tozer doing well to block the shot wide, as County brought on their first substitution of the afternoon.
That saw Labadie replaced by Scot Bennett in the midfield, as Mark O’Brien took over the captaincy duties.
But he only remained on the field for another 30 seconds, being replaced by Dan Butler, with Pipe becoming the third captain of the game.
The final substitution for the Exiles came with 60 seconds to go, goal scorer Amond replaced by Shawn McCoulsky, who made a welcome return to the team after not being involved since the Leeds United game through injury.
The indication of five additional minutes indicated it was time for Grimsby Town to throw everything at the Exiles, and Day had to make a smart save to deny Davies at the start of added time.
But in truth, the away side couldn’t muster any other opportunities as the Exiles saw out the victory with relative ease, as Amond settled the contest again for the second successive home game.
County: Day, Pipe, White, O’Brien (Butler 80’), Demetriou, Willmott, Labadie (Bennett 79’) (C), Rigg, Tozer, Amond (McCoulsky 89’), Nouble
Subs not used: Bittner, Dolan, Reynolds, Quigley
Grimsby Town: McKeown, Davies, Clarke (C), Collins, Dixon, Dembele (Jaiyesimi 71’), Berrett, Rose (Summerfield 45’), Woolford (Hooper 75’), Jones, Matt
Subs not used: Killip, Vernon, Cardwell, Osborne
Referee: Antony Coggins
Attendance: 3,356 (243 away)
Next up for County: Crawley Town (26th August) AWAY