The Spireites youth team advanced to the next round of the FA Youth Cup with a 3-2 victory after extra-time at Romulus on Friday night.
The home side took the lead with around a quarter of an hour gone after the Spireites defence failed to deal with a long ball played into the box.
Kian Tansley (35) scored the equaliser with a shot from just inside the area to make it 1-1 at half time.
Romulus took the lead in the second half when Chesterfield were caught by a sucker punch.
With a cup exit looking increasingly likely, the Spireites levelled a minute from the end when Callum Brook scored with a header to take the tie to extra-time.
Matt Fuertado scored the winner with a well-taken volley following a corner early in the first period of extra-time.
Coach Neil Cluxton said: "It was a tough evening with rain and strong wind making the conditions difficult.
They were strong and very direct, playing effective long balls. They had two quick strikers and some strong players. Our lads matched them and after the opening goal we started moving the ball around.
"We had a good chat at half time and I got the message across that we were the better team.
"It looked like we were going out of the competition before Callum Brook scored his second goal in two games, which is not bad for a centre-back, to take it to extra-time.
"After that, I was pretty confident, really. Romulus were very good, but I thought we were the deserved winners."
Cluxton says it sets his side up nicely for the home tie against Burton Albion during the week beginning November 4. "Seeing as though we beat them recently in the league, we're going into it with a bit of confidence," he added.
Spireites: Wharton, Tansley, Gibson, Geeves (Turner 83), Brook, Wilkinson, Emery, Fuertado, Papworth (Moore-Billam 84), Smith, Netherwood (Bradbury 69)
Unusued substitutes: England, Wild, Garwood & Clogg.