What an emotional rollercoaster for Notts County’s long-suffering supporters. But after twice seeing their side battle back from the jaws of defeat thanks to equalisers from John Bostock and Rúben Rodrigues that both required a large slice of fortune, it was all worthwhile as Luke Williams’s side returned to the Football League after four years away largely due to the heroics of the substitute goalkeeper Archie Mair.

The giant 22-year-old on loan from Norwich was brought on with seconds of extra time remaining for only his fifth appearance for the club and produced two brilliant saves in the penalty shootout to deny Darren Oldaker and Jeff King, with even a fluffed Panenka from Bostock unable to stop the party for the fans in black and white who made up the majority of the 38,000 crowd. It was a devastating way to lose for Chesterfield, who may have finished a whopping 23 points behind their opponents during the league season but were minutes away from claiming victory themselves on two occasions.

Related: Chesterfield v Notts County: National League playoff final goes to penalties – live

“It was horrific,” admitted the Notts County manager Williams. “But we want to go on a longer journey and to do that we need to take a breath and come through these challenging situations. I’m so pleased for the players.”

Only 26 miles separate these two clubs, who had both spent the vast majority of their existences in the Football League until falling through the trapdoor in the space of 12 months of one another. But while Notts County have finally earned promotion having reached the playoffs in each of their four seasons as a non-league club, all of Chesterfield’s supporters were long gone by the time the Wrexham owner Ryan Reynolds tweeted his congratulations. “What a game, what a season, what heart,” wrote the Deadpool star. “We will see you in the EFL next.”

Chesterfield’s impressive season under Paul Cook – the former Portsmouth and Wigan manager who returned for his second spell at the helm last year – included reaching the third round of the FA Cup and they ended the campaign with five wins from their last seven matches, beating Bromley after extra time in the semi-finals. But after also requiring a last-ditch extra-time winner from Jodi Jones against Boreham Wood to reach the final, it was Notts County who showed their ability to pick themselves up off the canvas after the disappointment of being pipped to the title by Wrexham despite scoring a club record 117 goals.

For most of this encounter it appeared that their campaign was doomed to end in failure, especially when Chesterfield were handed the initiative inside the opening 60 seconds in a nightmare start for their goalkeeper. Only Sam Slocombe will know what was going through his mind when he decided to take a goal kick to himself, although the 34-year-old slightly redeemed himself by blocking the resulting indirect free-kick. There was no escaping his second error when a flailing kick at Andrew Dallas as the Chesterfield striker attempted to shoot was immediately penalised, with Dallas making no mistake from the penalty spot.

This was the first time this game has taken place at Wembley in three years, with only 21,000 at West Ham’s London Stadium to see Grimsby’s promotion last year. That figure was easily surpassed by the Notts County supporters on their own as they filled out the whole of the lower and middle tiers, although they were forced to watch their side struggle to contain repeated Chesterfield attacks. Slowly but surely, however Bostock started to make things tick for Williams’s side. Macaulay Langstaff even managed to outscore Wrexham’s Paul Mullin – working as a television pundit for this match – with a National League record 42 goals for the season and he would surely have taken the chance that fell to Sam Austin after he was set up by Aaron Nemane, only for the midfielder to blaze over.

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Connell Rawlinson then headed wide before Liam Mandeville could have wrapped it up after a poor clearance from the unfortunate Slocombe and Chesterfield were made to pay a heavy price when Bostock squeezed his free-kick under the despairing Ross Fitzsimons with just three minutes of normal time remaining. Their fans were given reason to celebrate again when Armando Dobra curled home a fantastic effort at the start of extra time and jumped into Cook’s arms on the touchline. Yet again, however, their joy was shortlived as Rodrigues equalised two minutes into the second half of extra time with a volley that bounced over Fitzsimons before Mair came off the bench to steal the headlines.