Chesterfield boss John Sheridan criticised referee Lee Mason after his side`s undefeated home record was controversially ended in a 2-1 defeat to Burton.
The League Two leaders recovered from going a goal down but after midfielder Derek Niven was dismissed in the second half, Shaun Harrad came off the bench to win it for the Brewers.
Chesterfield were reduced to 10 men in the 57th minute when Niven was sent off for a late challenge and Sheridan said: "The sending off was shocking, I thought some of his decisions were shocking all day.
"He's a Premier League referee so I've heard but even the fourth official was telling me it was never a sending off and the linesman said it was never a sending off but he's telling us when he's walking off the pitch that it was a sending off."
Niven had equalised after James Collins` early opener but Harrad`s winner left Chesterfield empty-handed.
Sheridan added: "We will take it on the chin, we got beat, it's a shame we've lost our home record but hopefully he (the ref) will get the headlines for making a lot of mistakes and poor decisions."