A brilliant overhead kick from Chesterfield midfielder Chris Brandon earned his side their first points of the season.
The former Torquay man struck four minutes from time to add to an earlier goal by Rob Edwards as Port Vale's miserable start continued.
The away side started brightly and could have gone ahead on 34 minutes but Brett Angell saw his goalbound header from Marc Bridge-Wilkinson's corner cleared off the line by Edwards.
Just 34 seconds into the second half Edwards was in the thick of the action at the other end when he fired home from close range after Glynn Hurst's effort was blocked.
Angell then had a header well saved by Carl Muggleton before Brandon settled the issue with his spectacular strike from Gareth Davies' cross.
Mark Hudson then had a chance to make it three but his piledriver from the edge of the box was tipped over the bar by Mark Goodlad.
Angell hit an injury-time consolation from the penalty spot after he was tripped by Jon Howard, but it was too little too late for struggling Vale.
Afterwards disappointed Vale manager Brian Horton said: "The first half was alright but I was bitterly disappointed with the performance after the break.
"Players went missing after the first goal and it is up to me to put that right. The only way to get out of this position is to make things happen and be stronger and more competitive."
Chesterfield goalscorer Brandon added: "It is nice to get off the mark. That was the best goal of my career but I want ten for the season and hope the others are all like that."