James McKeown's penalty save secured 10-man Grimsby Town their first point of the season at Newport.
Goalkeeper McKeown saved Craig McAllister's tame spot kick after the striker was brought down on 77 minutes by last-man Darran Kempson, who was sent off for the challenge.
Newport were on the front foot for most of a scrappy and error-strewn match.
Tom Miller, Elliott Buchanan and Danny Rose all had chances but County failed to profit from Kempson's dismissal.
Newport County: Potter, Baker, Miller, Yakubu, Rodgers, Rose, Rogers (Gilligan 23), Doherty, Jardim, McAllister, Buchanan.
Subs Not Used: Thompson,Foley,Hughes,Hatswell.
Booked: Rogers, Yakubu, McAllister, Rodgers.
Grimsby: McKeown, Ridley, Kempson, Pearson, Wood, Disley, Artus, Thompson (Makofo 72), Coulson, Hearn (Elding 46), Duffy (Spencer 73).
Subs Not Used: Thanoj, I'Anson.
Sent Off: Kempson (78).
Ref: Robert Merchant (Staffordshire).