Chesterfield manager Gary Caldwell praised his defence after they kept their second clean sheet of the season.
Prior to the goalless draw against Coventry City, the Spireites had been leaking goals at an alarming rate.
The Spireites looked to be really up against it when Robbie Weir was sent off with a third of the match to go.
After shipping 17 goals in their first seven games, former defender Caldwell called for his side to get nasty and be more ruthless in stopping teams carving them open.
It was an improved defensive display at the Proact and it gave Caldwell reasons to positive going forward.
He said: “I’m absolutely delighted with the clean sheet, of course I am.
“It’s always pleasing for a manager when players respond in the way you want.
“We had to dig in at times, but that’s what happens when you go down to ten men.
“It’s a credit to those players that they didn’t give up because they easily could have.
“I think there were plenty of positives in that performance to give us encouragement going forward.”
Caldwell gave debuts to new boys Zak Jules and Matt Briggs and he was delighted with how they stepped up.
Jules joined on loan on deadline day on loan from Shrewsbury and Briggs was snapped up as a free agent.
Caldwell added: “I was really pleased with the way the new boys came in straight away and performed. They both played well and they’ve only been with us a couple of days.”
Tommy Lee made a super save to send Marc McNulty’s flying strike out for a corner.
New boy Matt Briggs looked the part at both ends of the pitch, getting forward at every opportunity - whilst putting in the tackles when needed in defence.
After taking some time to find their feet the Spireites started to create some decent chances. Jordan Flores was only denied by a superb stop from Lee Burge.
The hosts should have taken the lead just before the break. An error in the Sky Blues’ backline saw Kristian Dennis intercept Jack Grimmer’s woeful back pass, with Burge again making a fine save to tip Dennis’ effort over.
After the restart Lee once again did well to keep out a McNulty thunderbolt.
On the hour mark Weir was given his marching orders for bringing down Jodi Jones for his second booking.
The Spireites fought valiantly to keep the Sky Blues at bay after going a man down.
McNulty caressed an effort wide before Peter Vincenti headed home from an offside position.
Scot McNulty should have bagged the winner nine minutes from time as he nodded Anthony Andreu’s cross wide.