Match ends, Chesterfield 2, Scunthorpe United 0.
Sam Clucas struck twice in extra time as Chesterfield overcame Scunthorpe United to reach the fourth round of the FA Cup for the first time in 18 years.
The Spireites found visiting keeper Sam Slocombe in superb form and he denied Eoin Doyle twice in the first half.
Paddy Madden fired a shot just wide for the Iron, but when an extra 30 minutes was needed, midfielder Clucas turned in a low cross before settling the replay.
He curled a second from distance to set up a fourth-round trip to Derby County.
The last time Chesterfield qualified for round four, they famously went on to the semi-final stage in 1997, eventually losing to Middlesbrough.
The Spireites' FA Cup run has already been dramatic in 2014-15, after their second round win over MK Dons was ordered to be replayed when it was discovered they had fielded an ineligible player.
But Paul Cook's side, in seventh position and nine places above Scunthorpe in League One, have proved resilient in recent weeks and extended their unbeaten run to seven games to set up a short 28-mile trip to Derby County on 24 January.
In doing so, they ended Scunthorpe's 11-game unbeaten run which stretched back to October and but for Slocombe's heroics, would have sealed the match in normal time.
After thwarting Doyle brilliantly early on with a diving save, he produced a string of saves in normal time while his side threatened sporadically as they improved after the hour.
Substitute Terry Hawkridge went close for them in extra time when his bouncing volley needed a smart save from Tommy Lee, but moments after Armand Gnanduillet wasted an opening for the home side, Clucas made his mark.
He pounced at the back post to tap home at the end of a neat move and when Tendayi Darikwa produced a moment of quality on the wing, his delivery eventually fell at the feet of Clucas, who fired a bending effort home.
Scunthorpe United manager Mark Robins told BBC Radio Humberside:
"I thought we did really well to push them as close to the end as we possibly could do. I've said all along they've got a stronger FA Cup squad than we have.
"But, having said that, we've made the best of it and pushed them as far as we possibly could do so.
"We did ok in terms of our defensive strategy but turning that defence into attack wasn't great, especially in the first-half.
"In the second-half we got to grips with it a little bit more and managed to get higher up the field and try to press them a little bit higher up the field, which meant we could get everybody up the field and in better and more advance positions."
- 18BocoSubstituted forJonesat 91'minutes
- 5MorsyBooked at 84mins
- 15HumphreysSubstituted forRyanat 82'minutes
- 2NolanBooked at 35minsSubstituted forSparrowat 48'minutesBooked at 109mins
- 25BoyceBooked at 41mins
- 35OsbourneSubstituted forHawkridgeat 94'minutes
- 28McSheffreySubstituted forAdelakunat 56'minutes
- Keith Hill
- Shots on Target
Second Half Extra Time ends, Chesterfield 2, Scunthorpe United 0.
Armand Gnanduillet (Chesterfield) hits the bar with a right footed shot from outside the box from a direct free kick.
Eoin Doyle (Chesterfield) wins a free kick in the defensive half.
Foul by Miguel Angel Llera (Scunthorpe United).
Corner, Chesterfield. Conceded by Andrew Boyce.
Goal! Chesterfield 2, Scunthorpe United 0. Sam Clucas (Chesterfield) left footed shot from outside the box to the bottom left corner. Assisted by Armand Gnanduillet.
Eoin Doyle (Chesterfield) wins a free kick on the right wing.
Foul by Hakeeb Adelakun (Scunthorpe United).
Sam Morsy (Chesterfield) wins a free kick in the attacking half.
Foul by Matthew Sparrow (Scunthorpe United).
Foul by Armand Gnanduillet (Chesterfield).
Miguel Angel Llera (Scunthorpe United) wins a free kick in the defensive half.
Matthew Sparrow (Scunthorpe United) is shown the yellow card.
Foul by Armand Gnanduillet (Chesterfield).
Miguel Angel Llera (Scunthorpe United) wins a free kick in the attacking half.
Attempt missed. Alex Davey (Scunthorpe United) header from the centre of the box is just a bit too high following a corner.
Corner, Scunthorpe United. Conceded by Sam Clucas.
Second Half Extra Time begins Chesterfield 1, Scunthorpe United 0.
First Half Extra Time ends, Chesterfield 1, Scunthorpe United 0.