Match ends, Newport County 0, Mansfield Town 1.
Mansfield's Reggie Lambe struck for the second successive game to deliver a blow to Newport County's League Two promotion hopes.
Callum Elder set up Lambe's late chance and the latter's right-footed, close-range angled shot to the bottom left corner was unstoppable.
The Stags' win allowed them to climb one place to 17th as they followed up beating Dagenham & Redbridge 2-1.
County remain seventh after a sixth defeat in their last 10 games.
The hosts dominated for long periods, but were unable to take advantage.
And when Lambe's opportunity came, he calmly converted Elder's cross.
Newport manager Jimmy Dack told BBC Radio Wales:
"I can't put into words how I'm feeling at the moment.
"I'm really, really, really frustrated. I have to choose my words carefully here.
"The players - they give their all and anyone watching that game couldn't fault their effort. We just lack a little bit of guile in the final third… it's so frustrating."
Mansfield Town manager Adam Murray told BBC Radio Nottingham:
"It's a superb night. One of the days I've enjoyed in the job so far. I'll enjoy this for a few hours, it means a lot.
"A shout goes out for our fans, to get behind our boys like they did and have done in recent weeks. It's a huge three points.
"We always want to get better, but I'm so proud of the players that haven't been playing. To come in and give that kind of performance is superb.
"We'll enjoy the couple of hours home, but my mind is already on Cheltenham."
- 8MinshullSubstituted forSandellat 69'minutes
- 18KlukowskiSubstituted forPorterat 72'minutes
- 11ZebroskiSubstituted forParkerat 83'minutes
- 26ElderBooked at 86mins
- 7MonakanaSubstituted forLambeat 58'minutesBooked at 90mins
- 16HeslopSubstituted forThomasat 81'minutesBooked at 90mins
- 29KeeSubstituted forOliverat 83'minutes
- Andy Davies
- Shots on Target
Second Half ends, Newport County 0, Mansfield Town 1.
Reggie Lambe (Mansfield Town) is shown the yellow card.
Ryan Jackson (Newport County) wins a free kick on the right wing.
Foul by Reggie Lambe (Mansfield Town).
Attempt missed. Joe Parker (Newport County) header from the centre of the box misses to the right.
Jack Thomas (Mansfield Town) is shown the yellow card.
Foul by Jack Thomas (Mansfield Town).
Ryan Jackson (Newport County) wins a free kick in the defensive half.
Martin Riley (Mansfield Town) wins a free kick in the attacking half.
Foul by Miles Storey (Newport County).
Attempt blocked. Darren Jones (Newport County) right footed shot from outside the box is blocked.
Hand ball by Mark Byrne (Newport County).
Goal! Newport County 0, Mansfield Town 1. Reggie Lambe (Mansfield Town) right footed shot from the right side of the six yard box to the bottom left corner. Assisted by Callum Elder.
Callum Elder (Mansfield Town) is shown the yellow card.
Adam Chapman (Newport County) hits the bar with a right footed shot from outside the box.
Corner, Newport County. Conceded by Sascha Studer.
Attempt saved. Max Porter (Newport County) right footed shot from outside the box is saved in the bottom right corner.
Ryan Jackson (Newport County) wins a free kick on the left wing.
Foul by Vadaine Oliver (Mansfield Town).