Mansfield Town advanced into the fourth round of the Carabao Cup for the first time since 1975 after knocking out League One Peterborough on penalties in a breathless encounter at One Call Stadium.

Mansfield previously beat Championship Sheffield Wednesday on penalties in the previous round and Peterborough met the same fate after the game finished 2-2 in normal time.

Will Swan netted his first goal of the season via a penalty after five minutes before Posh hit back with a double strike from talisman Jonson Clarke-Harris.

And then came a late twist as Stags were awarded another  spot-kick in the second minute of added time as Macdonald was hurled to the ground. And Akins stepped up to expertly send the goalkeeper the wrong way to send the tie to penalties.

And while goalkeeper Christy Pym pulled off heroics in goal, substitute Davis Keillor-Dunn blasted home the final penalty to give Stags a 3-1 win on spot-kicks.

Five changes were made by Stags’ boss Nigel Clough from Saturday’s hard-fought 1-0 victory at home to Barrow.

Defenders George Williams and Baily Cargill, midfielders Hiram Boateng and George Maris along with forward James Gale, replaced Jordan Bowery, Calum Macdonald, Ollie Clarke, Davis Keillor-Dunn and Lucas Akins.

Peterborough, meanwhile, were unchanged from their 1-1 draw at Bolton on Saturday.

Posh flew out of the traps and almost broke the deadlock inside the third minute, but for a brilliant block on the goal line from Baily Cargill.

The visitors swept forward on the left flank and Ricky-Jade Jones pulled it back for marksman Jonson Clarke-Harris who rifled goalwards from eight yards, only to be denied by an outstanding defensive header on the line from Cargill.

Then, less than two minutes later, Stags were awarded a penalty from their first charge at goal.

Boateng squared for Maris who threaded a short pass into the penalty area for the advancing Will Swan.

And the 22-year-old peeled away from his marker before being tripped by Archie Collins, who was then booked after referee Sebastian Stockbridge pointed to the spot.

The ex-Forest man made no mistake from 12 yards as he coolly placed his right-footed spot-kick down the middle.

Stags’ tails were up and Maris struck wide in the tenth minute when Swan fed Lewis to pick out Maris on the right of the box. But the midfielder scuffed his effort and goalkeeper Nicholas Bilokapic went untroubled.

At the other end, Ephron Mason-Clark blazed over with a hopeful effort from 25 yards.

The same man came much closer in the 18^th minute as Stags’ goalkeeper Christy Pym – formerly of Peterborough – made a terrific one-handed stop in the 18^th minute.

The attacker showed lovely footskills to break into the box before unleashing a low attempt which Pym was equal to with a fine save low to his left.

Midway through the first-half, Lewis showed great tenacity to keep the ball in play in the corner flag and send it back to Williams on the right channel. And the right-back whipped in a crisp cross for Gale to nod wide from 12 yards.

Pym then stood tall at his near post to deny Jones’ strike from an acute angle.

Lewis went into the book for a foul on Mason-Clarke, 25 yards from goal, which led to Peterborough’s equaliser.

Clarke-Harris stepped up to blast a sizzling left-footed free-kick through the wall and blind-side Pym with the aid of  deflection in the middle of his goal.

Pym did well to tip over Hector Kyprianou’s header a minute later as Posh searched for the lead.

Darren Ferguson’s men began to dominate possession but Stags held them off until the break.

At the break, Jordan Bowery took the place of Lewis Reed.

But within a minute of the restart, Posh took the upper hand.

Kioso raced forward before firing goalwards and a back-tracking George Williams did superbly to momentarily hack it off the line. But he could do little about Clarke-Harris’ close-range finish.

Kioso almost grabbed a goal of his own on 51 minutes, denied only by Pym, who tipped onto the crossbar following a corner.

Posh piled on the pressure and Clarke-Harris went close when he flashed a shot narrowly beyond the post with 55 minutes played.

Stags made a treble change on the hour. Ollie Clarke, Lucas Akins and Calum Macdonald replaced George Maris, Baily Cargill and Will Swan.

Peterborough kept their foot on the accelerator and moments later, Clarke-Harris unleashed a ferocious left-footed free-kick from 20 yards which arrowed beyond the target.

Stags suddenly put Posh under the cosh and attacked with a new-found vigour.

Nigel Clough’s side had a penalty appeal waved away on 66 minutes when Lewis was bundled down in the area.

Stags started to go for the throat and Lewis controlled well from a high ball on the right of the penalty before laying it back to Jordan Bowery. And Stags’ number 9  saw his low 25-yard drive well stopped by Bolokapic at his near post.

From a free-kick, Gale struck into the side netting from a tight angle with the help of a deflection for Stags’ second corner of the night.

Mansfield’s golden chance for a leveller came following the flag-kick on 69.

Boateng’s cross-cum-shot was deflected goalwards and looked to be looping over the goalkeeper and into the net, but James Gale headed it over for a goal kick from three yards.

Stags had a goal ruled out for offside three minutes later. Gale beat his man to send a low cross into the box and Akins got beyond a defender to finish but the flag was up.

On 75, Davis Keillor-Dunn was introduced for George Williams and Posh made their first change of the night as David Ajiboye replaced Ricky-Jade Jones.

Stags kept pushing for an equaliser and Macdonald spotted the goalkeeper off his line but his audacious long-range attempt sailed wide of the left post.

On 88, Aden Flint and Mason-Clarke were booked for an altercation before Posh made a double change.

In stoppage time, Flint was sent up front and headed against the goalkeeper.

There was no respite from the amber and blue and the pivotal moment of drama unfolded on 92 minutes as Macdonald was bundled to the ground inside the area by Clarke-Harris as Stags were given a second penalty.

And Akins duly obliged from the spot with a superb low finish into the bottom right corner to send the goalkeeper the wrong way.

The spot kicks were taken in front of the Posh supporters at the North Stand end of the ground.

Akins put Mansfield ahead with a low right-footed finish which flew under Bilokapic.

Pym pulled off a magnificent one-handed stop to his right to deny Clarke-Harris in Posh’ first penalty.

Bowery directed his low drive into the bottom left-corner to make it 2-0 to Mansfield.

Ronnie Edwards sent his down the middle but again Pym was the hero as he stood firm to claim.

Aden Flint hammered his attempt against the left post.

Mason-Clarke grabbed Posh’s first goal with a right-footed finish.

Ollie Clarke saw his strike saved.

Josh Knight missed, leaving Mansfield needing one more goal to advance into the next round.

And Stags’ leading goalscorer sealed the victory as Davis Keillor-Dunn sent the goalkeeper the wrong way to cap off a thrilling night at One Call Stadium.

STAGS: Pym, Williams (Keillor-Dunn 75), Flint, Brunt, Cargill (Macdonald 61), Reed (Bowery HT), Lewis, Boateng, Maris (Clarke 61), Gale, Swan (Akins 61)

UNUSED SUBS: Flinders, Cooper, Flanagan, Abdullah

POSH: Bilokapic, Burrows, Edwards, Knight, Clarke-Harris, Mason-Clark, Poku, Jones (Ajiboye 75), Kyprianou, Collins, Kioso

UNUSED SUBS: Talley, Katongo, Crichlow, De Havilland, Randall, Sturge, Fernandez, Corbett

REFEREE: Sebastian Stockbridge

ATTENDANCE: 4,372 (682 Posh fans)