Call that a comeback? Napoli recovered from 2-0 down to draw with Milan in a barn-burning Sunday night game, Matteo Politano and Giacomo Raspadori setting the Stadio Diego Armando Maradona ablaze with spectacular second-half goals to cancel out Olivier Giroud’s pair of first-half headers. A giddy, seesawing clash between the reigning champions and opponents who hope to dethrone them, yet still only the second-best turnaround of the Serie A weekend.

That is because Cagliari did something no team had ever done in the Italian top-flight: recovering from three goals down after the 70th minute to win against Frosinone. Their manager, Claudio Ranieri, has achieved greater miracles in his career, but not many. His team had previously collected three draws and six defeats from nine games.

Of the three newly promoted sides, Cagliari had looked most out of their depth. In part that could be blamed on the absence of Gianluca Lapadula, Serie B’s leading scorer last season, who underwent ankle surgery in the summer. But the Sardinians were also frequently overrun in midfield, where only Antoine Makoumbou seemed capable of protecting and advancing possession.

Not that Ranieri was ever worried. Before Sunday’s game, he told reporters: “I’m sure we’ll keep ourselves in Serie A the same way we got here: in the last second of the last game of the season.”

Cagliari were joint-12th in Serie B when Ranieri took over last December. They climbed to fifth in time for the promotion playoffs, which they then navigated in the most dramatic way possible. After recovering from 2-0 down to beat Parma 3-2 in the semi-final, they were drawing 1-1 on aggregate with Bari in the 94th minute of the final’s second leg.

In effect, they were losing. There are no away goals or penalty shootouts in the Serie B playoff final – in the event of a draw, the team who finished higher in the table are promoted. Bari, who placed third, only needed to hold on a few more seconds. But under torrential rain at their Stadio San Nicola, Leonardo Pavoletti, who had only been on the pitch five minutes, delivered victory for Cagliari instead.

Frosinone’s path to promotion was far more serene. They finished seven points clear at the top of Serie B and made a bright start to life in the top flight too, beating Atalanta and Sassuolo in their first two home games.

Despite spending just €4.4m in transfer fees, they made several smart additions in the summer. Walid Cheddira, star of that Bari team whose hearts were broken by Cagliari, was picked up on loan, as was the promising Brazilian playmaker Reinier Jesus from Real Madrid. Both had flashed their potential already this season, but the real star of the show has been Matías Soulé.

Another loanee, this time from Juventus’s Next Gen team, the Argentinian winger has dazzled in almost every game he has played at Frosinone: showcasing not only lightning acceleration and dizzying dribbles but also a rare capacity to read a defence and thread the needle with his passing at 20 years old. He has even excelled in the air, his first two goals arriving from headers.

For 71 minutes on Sunday, it appeared Soulé’s performance would be the story of the game against Cagliari. He both created and converted the game’s opening goal, pouncing on an underhit pass from Alberto Dossena and playing a one-two with Reinier before finishing coolly at the near post.

A left-footer, Soulé lines up as an inverted winger on the right of Frosinone’s formation, and it was no accident that almost all his team’s play was channelled down that flank again on Sunday. Yet his second goal came from the opposite side. Soulé had drifted across to receive another pass from Reinier and tormented Dossena once again as he feinted left and then cut the other way, scoring off his weaker right boot.

Marco Brescianini made it 3-0 to Frosinone just after the interval. That scoreline did not reflect the balance of play – Marco Mancosu hit the woodwork twice for Cagliari in the first half, the first time from a penalty – yet any comeback now appeared impossible.

Good thing they have Ranieri as manager. “I always hope for impossible things,” he would tell reporters after the game. “You must never give up; you have to battle until the last second. If you give up sooner than that you have not done your job.”

He had been forced into a substitution before half-time, Nahitan Nández exiting with an injury. He made a second during the break, sending Pavoletti on to replace Alessandro Deiola – a centre-forward for a midfielder. After Brescianini’s goal, he continued with three more changes, introducing Gaetano Oristanio, Nicolas Viola and Paulo Azzi.

It was the first of that trio who provided the spark, curling an excellent finish into the bottom corner in the 72nd minute. This was Oristanio’s first Serie A goal, but the 21-year-old, on loan from Internazionale, did not celebrate, simply turning and running back toward the halfway line as a teammate went to retrieve the ball from the net.

Four minutes later, Cagliari scored again, Makoumbo stealing possession from an inattentive Brescianini and side-footing the ball past the goalkeeper, Stefano Turati. Now the stadium was rocking. Only one more goal was needed to draw the home team back level.

Cagliari thought they would get their chance almost immediately, when the referee, Luca Pairetto, pointed to the penalty spot after Turati went through Pavoletti. But the decision was overturned by the VAR booth, who judged that the goalkeeper had got to the ball first.

Instead, they had to wait until the fourth minute of injury time for an equaliser. When Pavoletti rose to head home Viola’s cross, the impossible comeback appeared to have been completed.

Only, Cagliari still weren’t finished. They wanted to win this game, not just to draw it. Makoumbo lifted one last ball into the Frosinone area, Dossena nodded it down and Pavoletti – somehow, always Pavoletti – hooked it home to unleash pandemonium at the Unipol Domus stadium.

Aged 34, Pavoletti has become the symbol of a team that never quite knows when it’s beaten. Ranieri compared him on Sunday to the former Milan, Napoli and Juventus striker José Altafini, saying that: “Whenever Juve really needed a goal, they would stick him on and he would score it.”

A knowingly generous comparison. Altafini won a World Cup with Brazil as well as a European Cup and four Serie A titles in his club career. Pavoletti is a journeyman No 9 who sometimes looks as if he belongs to a different era: a tall, physical target man who never quite smoothed off the rough edges, producing some prolific seasons but also too many quiet ones.

Genoa 1-0 Salernitana, Juventus 1-0 Verona, Lecce 0-1 Torino, Sassuolo 1-1 Bologna, Napoli 2-2 Milan, Internazionale 1-0 Roma, Monza 1-1 Udinese, Cagliari 4-3 Frosinone

Monday Empoli v Atalanta, Lazio v Fiorentina

He is enjoying this chapter as Cagliari’s last action hero. Pavoletti posted a picture of himself grinning to Instagram on Sunday night with the caption: “The face of someone who still believes in dreams.”

Who better to chase those with than Ranieri, the man who led Leicester to an impossible league title and decided not to leave it at that?