Match ends, Newport County 2, Grimsby Town 0.
Striker Padraig Amond continued his FA Cup heroics as Newport edged out 10-man Grimsby to reach the second round.
Amond's cool finish after 50 minutes was his eighth FA Cup goal in the last seven rounds of the competition, with Amond scoring in each and every round.
Midfielder Joss Labadie lashed home a second just after Mattie Pollock was sent off for the visitors.
Newport face a trip to eighth tier Maldon & Tiptree in round two on Friday, 29 November (19:55 GMT).
The victory means Newport continue their FA Cup love affair after they reached round five last season and round four in 2018.
The Exiles will be dreaming of another financially transformative FA Cup run, with the visit to Essex in round two set to boost the club finances to the tune of £75,000 and with Newport heavy favourites to advance to round three.
Prize money and television fees will earn Newport a guaranteed £180,000 if they beat their Isthmian League North Division opponents.
It took them a while to get going at a freezing Rodney Parade in a first half that was not exactly a good advert for the FA Cup, or League Two football in general, as both goalkeepers were virtual spectators.
The visitors had plenty of possession but little cutting edge, while Newport did not trouble James McKeown until injury time when Ryan Inniss' close-range header was straight at the Grimsby goalkeeper.
However, the Exiles went ahead with a real moment of quality as they caught the Mariners cold with a super counter-attack. Josh Sheehan's clever through ball was collected by Corey Whitely and his pinpoint cross was stroked home by Amond.
Newport beat Leeds United and held Tottenham Hotspur two years ago, and last year thrilled their fans with victories over Leicester City and Middlesbrough before being eliminated by Manchester City.
They will now be looking ahead to more potential glory in the competition after they proved too strong for the managerless Mariners, whose threat subsided dramatically in the second half.
Amond might have added a second but his lob was easily saved by McKeown, while at the other end Ahkeem Rose fired straight at Newport's Nick Townsend.
Newport held on comfortably to their 1-0 lead which was all but secured when Grimsby sub Pollock was sent off for a second yellow.
The Exiles killed the contest moments later when Labadie lashed home off the underside of the crossbar after McKeown blocked his initial effort.
Liam Gibson blasted over with a late chance for the visitors but it is Newport who will now be dreaming of another lucrative run in the FA Cup.
Newport County manager Michael Flynn told BBC Sport Wales:
"We are through, that is the most important thing in the Cup. We didn't play well in the first half but second half we were much better.
"We will be the favourites in the next round, of course, so we know we need to go there with the right attitude and we won't be resting players or playing a weakened team.
"We have watched Maldon & Tiptree already and we will not be taking them lightly, it is going to be tough, they are in good form.
"Financially it is massive, we have already made a small fortune this season... it could make a really big difference in January."
- 20WhitelySubstituted forMattat 75'minutes
- 10SheehanBooked at 85mins
- 15AbrahamsBooked at 47minsSubstituted forPoleonat 90+4'minutes
- 9AmondSubstituted forDolanat 90'minutes
- 22HewittSubstituted forWhitehouseat 82'minutes
- 25PollockBooked at 90mins
- 7GreenSubstituted forCardwellat 55'minutes
- 14RoseBooked at 52minsSubstituted forCliftonat 79'minutes
- Darren Handley
- Shots on Target
Second Half ends, Newport County 2, Grimsby Town 0.
Attempt missed. Liam Gibson (Grimsby Town) left footed shot from the left side of the box is just a bit too high.
Josh Sheehan (Newport County) wins a free kick in the defensive half.
Foul by Harry Davis (Grimsby Town).
Attempt saved. Joss Labadie (Newport County) right footed shot from the centre of the box is saved in the centre of the goal.
Substitution, Newport County. Dominic Poleon replaces Tristan Abrahams.
Goal! Newport County 2, Grimsby Town 0. Joss Labadie (Newport County) left footed shot from the centre of the box to the top left corner.
Second yellow card to Matthew Pollock (Grimsby Town) for a bad foul.
Jamille Matt (Newport County) wins a free kick in the attacking half.
Foul by Matthew Pollock (Grimsby Town).
Substitution, Newport County. Matthew Dolan replaces Padraig Amond.
Josh Sheehan (Newport County) is shown the yellow card for a bad foul.
Foul by Josh Sheehan (Newport County).
Harry Clifton (Grimsby Town) wins a free kick in the defensive half.
Corner, Newport County. Conceded by Luke Waterfall.
Attempt blocked. Ryan Inniss (Newport County) header from the centre of the box is blocked.
Substitution, Grimsby Town. Elliott Whitehouse replaces Elliott Hewitt.
Attempt missed. Robbie Willmott (Newport County) right footed shot from outside the box is high and wide to the right.
Joss Labadie (Newport County) wins a free kick in the attacking half.