Padraig Amond's goal was his 12th in the league this season
Newport ended Accrington Stanley's 15-game unbeaten run to prolong their wait for the League Two title.
Padraig Amond's first-half strike after half-hour handed Michael Flynn's men the lead before Frank Nouble rifled home with five minutes remaining.
Mark Hughes hit the post for Accrington at 1-0 as they pushed for the draw that would have ensured top spot.
Billy Kee's 90th minute effort was not enough for Accrington, as they will try again at home to Lincoln on Saturday.
Accrington Stanley manager John Coleman: "It's something we're not used to. For a long while we've been superb but we didn't turn up in the first-half and they were comfortably better than us.
"I feel sorry for those who made the trip and wanted a party, but when you come to places like this they're not going to want to let you party in their back garden."
Newport County manager Mike Flynn: "I thought we were excellent. It was a slow start but we grew into the game and we should have scored more and been a lot more comfortable. I'm still waiting to win a game without my blood pressure going through the ceiling.
"I've never given the instructions to sit back - if you do this against a team like this you're asking for trouble. They'll win the league, 100%, but I'm just glad they didn't win it here."
