Chesterfield manager Paul Cook admitted defeat to Mansfield Town has left his players hurting.
The Spireites lost their unbeaten record in League Two at the hands of their arch-rivals, despite dominating for large periods.
Calvin Andrew’s first half header sent the travelling yellow army back down the A617 with the bragging rights, as they chalked up their first win over Chesterfield in 10 years.
Cook said: “When teams get behind the ball it can be long afternoons for us. We’re hurting as a dressing room right now.
“We started the game ever so well. We were bright and we had chances to score. It’s easy for me to make excuses but I think Mansfield deserve great credit.
“They’ve come here with a game plan and it’s worked for them. We’ve had a lot of plaudits over the last couple of months so today we’re going to show a little bit of class and a little bit of manners and say well done to Mansfield.”
He added: “Three points come and go every week, but today it’s for the bragging rights and unfortunately we’ve let our supporters down today. We’ll have our day soon with them and that’s something our supporters can look forward to.”
Chesterfield had a strong claim for a penalty turned down when Sam Morsy seemed to have been clipped with the goal at his mercy.
But Cook said: “There’s no excuses from me in football. Sometimes you get the decisions, sometimes you don’t. We’ve been beaten by Mansfield and we’ve got to take it on the chin.
“It’s tough and the next few days will be hard work but when we look at the league we’re top, yet it feels like we’ve been relegated. It’s what football can do to you.”
Gary Roberts was shown a straight red card for stamping on James Jennings off the ball deep into injury time to cap off a disappointing day for Chesterfield.
Cook added: “Gary wants to deliver so much for everyone and sometimes when it’s not your day it can lead to that. Gary’s a great lad and that’s totally out of character for him.”