Aaron Collins of Newport County holds off the challenge from Laurence Maguire
Already-relegated Chesterfield beat Newport in a rearranged fixture after snow postponed the original meeting in April.
Newport had the first half's best chance when Padraig Amond rounded Aaron Ramsdale in the home goal, but his deft effort was cleared off the line.
But it was the hosts who found an opening on 70 minutes when Kristian Dennis headed home Louis Dodds' cross.
Chesterfield stay bottom despite victory; Newport remain in 11th.
The visitors would have sealed a top-half finish with what would have been their third win in a row after beating Accrington Stanley and Cambridge last week.
Newport County manager Michael Flynn: "We created enough chances in the first half to win two or three games but our end product was bad which we spoke about at half time.
"It went the other way in the second half though, it wasn't helpful that we had to make loads of changes, the boys gave everything.
"I'm not going to read the riot act, the boys are flat on their feet and that's from all their efforts this season."
- Published28 April 2018
- Published24 April 2018
