Match ends, Chesterfield 3, Huddersfield Town 5.
Managerless Huddersfield fought back from two goals down to beat Chesterfield in extra-time and reach the Capital One Cup second round.
Ritchie Humphreys headed in Chesterfield's opener, before Ollie Banks added a second.
Nahki Wells's header made it 2-1 but Eoin Doyle tapped in for the hosts.
A Wells penalty and a Stead strike took the game to extra time, where a third for Wells and a Joe Lolley goal put Championship side Huddersfield through.
It was a welcome result for Huddersfield after a dramatic start to their season.
They lost 4-0 at home to Bournemouth on Saturday and parted company with former manager Mark Robins the following day.
Mark Lillis was named as caretaker at the start of the week but the change initially appeared to have had little impact, as League One promotion hopefuls Chesterfield took the lead midway through the first half.
The 37-year-old Humphreys got between the Huddersfield defence to head in Daniel Jones's ball into the box.
Huddersfield went close soon after through Danny Ward but his snapshot was saved and Chesterfield instead went on to grab a second, Banks launching a fine 25-yard strike into the back of the net just before the break.
A change in formation saw an improvement from the visitors in the second and they started to dominate.
They got themselves back into the game just before the hour when Oliver Norwood delivered a teasing cross into the area and Wells nodded in, only for hopes of a fight back to be seemingly ended by Doyle's close-range finish.
But Huddersfield showed impressive resolve as Stead was fouled inside the area and Wells converted from the spot to make it 3-2 before Stead pounced on a mistake in injury time to send the game into extra-time.
Lillis's side took the lead for the first time in the 94th minute when Wells completed his hat-trick, firing in after Stead's shot was saved.
Substitute Lolley then sealed Huddersfield's progression minutes later with a confident finish after being sent clear.
Chesterfield manager Paul Cook:
"You've got to give great credit to Huddersfield for coming back and we wish them the best of luck. We have to get behind the players and continue to back them when they make mistakes.
"It's been well documented what's gone on at Huddersfield but they are a fantastic club and you only have to look at the calibre of players they've got.
"They can do teams serious damage and tonight they've hurt us."
Huddersfield caretaker manager Mark Lillis:
"The lads showed character. At 3-1 down I looked at the clock with eight minutes to go and the fans were singing 'you're getting sacked in the morning' but I'm only the caretaker so I had a chuckle.
"All the squad have been fantastic and what pleased me was that in the 118th minute there were lads blocking shots on the line.
"We needed a win tonight but to do it like we did will give everyone a lift. I believe I will be in charge on Saturday and although it's difficult sometimes when you are a caretaker, I've got to make sure the players believe in me and I believe in them."
- 8RyanSubstituted forGnanduilletat 95'minutes
- 18BocoSubstituted forJohnsonat 57'minutes
- 15HumphreysSubstituted forBanksat 43'minutes
- 7ScannellSubstituted forMajewskiat 66'minutes
- 4NorwoodSubstituted forHammillat 81'minutes
- 11WardSubstituted forLolleyat 86'minutes
- Gary Sutton
- Shots on Target
Second Half Extra Time ends, Chesterfield 3, Huddersfield Town 5.
Attempt saved. Joe Lolley (Huddersfield Town) right footed shot from the centre of the box is saved in the centre of the goal.
Foul by Sam Morsy (Chesterfield).
Adam Hammill (Huddersfield Town) wins a free kick in the defensive half.
Corner, Chesterfield. Conceded by Lee Peltier.
Foul by Armand Gnanduillet (Chesterfield).
Lee Peltier (Huddersfield Town) wins a free kick in the attacking half.
Attempt missed. Radoslaw Majewski (Huddersfield Town) left footed shot from the centre of the box is close, but misses to the left.
Attempt saved. Armand Gnanduillet (Chesterfield) right footed shot from outside the box is saved in the top centre of the goal.
Armand Gnanduillet (Chesterfield) wins a free kick in the defensive half.
Foul by Lee Peltier (Huddersfield Town).
Ian Evatt (Chesterfield) wins a free kick in the attacking half.
Foul by Nahki Wells (Huddersfield Town).
Foul by Oliver Banks (Chesterfield).
Conor Coady (Huddersfield Town) wins a free kick in the attacking half.
Attempt missed. Joe Lolley (Huddersfield Town) header from the centre of the box is just a bit too high.
Second Half Extra Time begins Chesterfield 3, Huddersfield Town 5.
First Half Extra Time ends, Chesterfield 3, Huddersfield Town 5.
Foul by Sam Morsy (Chesterfield).