John Sheridan felt the home victory over rivals Sheffield Wednesday showed just how far Chesterfield have progressed recently.
The Spireites have struggled since making the step up to League One as champions last season, spending much of the campaign rooted to the foot of the table. However, results have started improve, with wins home and away against Oldham to reach the Johnstone's Paint Trophy final evidence of that.
The 1-0 triumph over the promotion-chasing Owls leaves Sheridan's side in 22nd place and just four points adrift of safety.
"We would have lost that game two or three-nil before and I think over the last 10 or 11 games we have really improved as a team, especially defensively," said former Wednesday player Sheridan.
"We battled really well against a really good team. After the first 10 or 15 minutes I thought 'here we go' because Wednesday put us under a lot of pressure, but I thought once we weathered the storm we really got into the game. I said to the lads at half-time to stay in the game and keep it tight and luckily for us we got the break."
Dean Morgan struck the only goal of the game from the penalty spot 12 minutes from time.