The penultimate weekend of the Serie A weekend was overshadowed by events off the pitch. On Friday, Juventus announced they had fired their manager, Massimiliano Allegri, citing his behaviour at the end of their Coppa Italia final triumph over Atalanta. Two days later, as Inter prepared to mark their league title with a trophy lift at San Siro, fans were wondering who their club would belong to next week.

Monday marked the official deadline for their owners, Suning Capital, to repay debts of close to €395m to Oaktree Capital, stemming from a loan taken out in 2021. A bank holiday in Luxembourg effectively extended the term until Tuesday, but an official statement from the Inter president, Steven Zhang, on Saturday accused the lender of “a lack of meaningful engagement” toward finding an “amicable resolution”.

Related: Juventus fire Massimiliano Allegri over his behaviour in Coppa Italia final

What comes next for either club? Paolo Montero, the Juventus Under-19s coach, will serve as their caretaker manager until the end of the season, but the hunt for a permanent replacement had already begun. Meanwhile, Oaktree is expected to take control of Inter if Suning cannot repay its debt – much as Elliott Management did with their neighbours Milan in 2018.

These, though, are stories that will rumble on for a while yet. It would be a shame if they distracted us completely from the football at a moment when there is still so much drama unfolding. This was a weekend when Claudio Ranieri completed his latest opus: guiding Cagliari to a 2-0 win at Sassuolo that guaranteed his club’s place in Serie A for another year, while condemning their opponents to relegation.

Most of the world might associate Ranieri above all with the Premier League title he won at Leicester: an achievement that only feels more extraordinary with the passing of years. In Cagliari, though, they have a story all of their own about the man who led them out of the footballing wilderness almost four decades ago.

Cagliari were at a low ebb in 1988, playing in Italian football’s third tier. They finished one point above Serie C1’s relegation zone in the season before Ranieri arrived. Over the next three seasons, he led them to consecutive promotions and then top-flight safety – even after they had been rooted to the bottom of the table at the midway stage.

Ranieri departed, venturing all over Europe and taking turns at Italy’s richest and most prominent clubs. He even had two stints with Roma, the team he supported as a boy, but back in Cagliari they always considered him one of their own: an adopted Sardinian whose voyage toward coaching at the highest levels had begun right there on the island.

Fans were delighted by news of his appointment last January, a prodigal son returning after 32 years away. Even then, few might have predicted his impact. Cagliari were joint-12th in Serie B, but went on to secure promotion via the playoffs, coming from two-goals down to beat Parma in the semi-final then winning the final against Bari with a goal in the 94th minute of the second leg.

How did he keep doing it? Older fans still remember the comeback Ranieri pulled off against soon-to-be champions Sampdoria during the relegation escape of 1991, recovering from 2-0 to 2-2 inside the last 20 minutes. This season’s Cagliari side went two better, turning a 3-0 deficit into a 4-3 win against Frosinone in October.

The path to safety has been a winding one. Ranieri offered to resign in February after a home defeat against Lazio left Cagliari 19th. They had lost 14 out of 24 matches and in the changing room he told his players: “If I’m the problem, tell me now and I’ll go and hand in my notice.”

According to the newspaper La Repubblica, it was the striker Leonardo Pavoletti who spoke for the group, telling Ranieri: “We’re working like crazy. We’re united. This wheel will turn.” Right on cue, it did. Cagliari drew their next match at Udinese, launching a run of 13 games in which they have suffered only three more defeats.

The sequence only looks more impressive when you consider some of the teams they have faced along the way. There was a two-week stretch when Cagliari beat Atalanta and then drew 2-2 with both Inter (who had not yet sewn up their title) and Juventus. The Bianconeri needed an 87th-minute own goal for an equaliser.

There has been no one star player carrying Cagliari. Their leading scorer, Nicolas Viola, is a 34-year-old who has only started 10 games and found the net five times. The January signings of Yerry Mina and Gianluca Gaetano certainly helped, the former becoming a fixture at centre-back and the latter adding another four goals while being deployed in various roles across the midfield and attack.

But this has been a season to remind us of why Ranieri was once the ‘Tinkerman’, reshuffling his pack constantly according to the opponent and his own players’ form and fitness. Cagliari’s formation has often been a variation on 4-4-2, but we have seen a back-five here, a Christmas Tree there, and 4-2-4s when the situation demands it.

Fiorentina 2-2 Napoli, Torino 3-1 Milan, Lecce 0-2 Atalanta, Roma 1-0 Genoa, Inter 1-1 Lazio, Udinese 1-1 Empoli, Monza 0-1 Frosinone, Sassuolo 0-2 Cagliari

It was the substitute midfielder Matteo Prati who put them in front against Sassuolo on Sunday, sweeping home left-footed after the ball was prodded to him by Alberto Dossena. The win was sealed with a penalty from Gianluca Lapadula in injury time – a joyful moment for a man who was Serie B’s top scorer last season but struggled to make an impact back in this campaign after a long recovery from summer ankle surgery.

Around 4,000 Cagliari supporters had travelled to the Mapei Stadium, and the celebrations made it all worthwhile. How many of them had been present exactly 33 years before to see their team secure top-flight survival under Ranieri at Bologna, less than an hour’s drive away, on 19 May 1991?

This is not the end of a story. Ranieri, at 72, has said before that he could imagine coaching into his 80s, joking that he would hobble to the dugout with a walking stick if his mind was still willing. He did not have to worry about that on Sunday, as the same players he had offered his resignation to three months before carried him triumphantly on their shoulders.

The city of Cagliari lost its greatest football hero, Gigi Riva, in January, a player who scored 164 goals for his hometown club and fired them to their only Serie A title in 1970. On Sunday, Ranieri recalled a conversation they’d had after beating Bari to secure promotion back to the top flight last summer, saying: “Gigi asked me to tell the lads that it’s not just the fans in the stadium with us, but an entire island.”

Ranieri could never overtake Riva in supporters’ affections, but these days he might run a close second. He has one year left on his deal at Cagliari but the club’s president, Tommaso Giulini, insisted: “Contracts don’t exist in his case. He can go on as long as he wants to. For as long as he has the fire inside him.”