The crowd roared with delight. As Victor Ibarbo wheeled away to celebrate scoring Cagliari's opening goal against Sampdoria, the home fans danced, hugged and held their scarves aloft. For a few seconds they cheered, too, before the ringleaders led them seamlessly into a series of sharply co-ordinated chants.

Ibarbo, though, barely heard a peep. For a while he was celebrating with his team-mates on the pitch at Cagliari's Is Arenas stadium, the fans in question were not inside the ground at all. Instead the group – roughly 100 strong – had congregated in a street outside, listening to the game on portable radios. A line of police officers in riot gear stood between them and the nearest entrance.

For Cagliari, it is becoming a familiar routine. This was the third time they had played behind closed doors this season – and the second in as many home games. Their match against Roma in September would also have been played under such circumstances, had Cagliari's president Massimo Cellino not invited the team's fans to defy an official ruling and show up anyway. As a result that fixture had to be abandoned altogether.

This is not how it was supposed to be. When Cellino moved Cagliari to the Is Arenas last summer, it was intended as a quick and easy solution to the team's problems at their previous home. For years he had been attempting to persuade local authorities of the necessity for upgrades to the communally-owned and increasingly run-down Stadio Sant'Elia. Finally, Cellino's patience had snapped, and he had instead opted to relocate altogether.

The Is Arenas, situated in the neighbouring suburb or Quartu Sant'Elena, was overseen by a different city council altogether, and this one Cellino found altogether more amenable. The stadium's existing structure was far too small for a top-flight team, but plans were drawn up to erect four temporary stands over the running track. Made out of steel and prefab materials, they weren't much to look at, but they were quick to put up and increased the venue's capacity to 16,500.

Or at least they did in theory. In practice, when the stadium finally did open to supporters for the first time in late September, only 5,000 or so season ticket holders were allowed in to watch Cagliari's home game against Pescara. That remained the case right through to mid-November, as the club worked to resolve enduring safety concerns. The police had expressed concerns over stadium layout, and specifically how crowds could be managed both inside and out.

The rest of the stadium was opened up over the next few months, but even then it was clear that not all issues had been resolved. Cagliari's game against Juventus in December was moved at short notice to Parma – almost 400 miles away. Nevertheless, the decision to play last month's match against Torino behind closed doors came as a shock to fans. A fortnight earlier 15,000 had watched Cagliari's draw with Milan at the Is Arenas.

Cellino had been arrested in the interim, on charges of embezzlement and false representation. It was alleged that a large sum of public money – reported in the newspapers at close to €750,000 – had been diverted away from its intended use to instead be spent on the construction of the Is Arenas. The Mayor of Quartu Sant'Elena, Mauro Contini, was also arrested, as was the public works assessor Stefano Lilliu.

All three have maintained their innocence, but neither Contini nor Lilliu has been quite as well-supported as the Cagliari owner. While Cellino was being held at Buoncammino prison, a group of Cagliari fans set up a vigil outside – singing his name and displaying messages of support. The players dedicated subsequent wins over Pescara and Torino to their incarcerated employer.

The authorities were keen to move Cellino from prison to house arrest, yet he resisted – saying he would rather wait to walk out free and fully vindicated. The cynics wondered whether there might be another factor at play. Those two victories had, after all, increased the buffer between Cagliari and the relegation zone from four points to 10.

Cellino is a famously superstitious man. In September 2011 he published a statement on Cagliari's official website imploring fans to wear the "unlucky" colour purple to a game against Novara in 2011 in order to cancel out the effects of playing on the 17th of the month – 17 being an equally "unlucky" number to his mind.

If superstition was a factor in Cellino's thinking on this occasion, too, then he might consider it to have been fully justified. One day after he was moved out of Buoncammino prison last weekend, Cagliari lost 3-0 to Bologna.

Placing Cellino under house arrest, though, was easier said than done. The owner's primary residence is in Miami, so he was instead moved to a private residential area at a criminal rehabilitation facility in Villamassargia, just outside Cagliari. That lasted for all of a week, Cellino's lawyers decrying the conditions as "similar to a concentration camp".

Instead, their client has now been relocated to his football club's training centre in Assemini. There Cellino has the luxury of several rooms at what is considered one of the best practice facilities in Italy. Although barred from communicating with the outside world outside of his heavily restricted visiting hours, Cellino does have a television. He will doubtless be aware of the protest march his players led through the city on Saturday.

A thousand fans, former players and members of club staff joined their procession through Cagliari, demanding the reopening of the Is Arenas. Cagliari's captain, Daniele Conti, and goalkeeper, Michael Agazzi, led the way, carrying a banner with the simple message: "Open the doors." Daniele Dessena and Davide Astori took turns to shout similar slogans through a megaphone.

The march came to an end in piazza Yenne but the protest continued through the weekend. A few hours later, on Saturday evening the entire Cagliari board resigned – defining the action as a show of support for the fans. On Sunday the team's players warmed up for their game against Sampdoria in T-shirts describing themselves as "sons of a lesser God".

Whether such actions will have any bearing on the future reopening of the stadium remains to be seen. In the meantime all that can be said is that the siege mentality built up around the club in these recent weeks certainly does not seem to be doing them any harm on the field.

Sampdoria ought to have represented stiff opposition this Sunday. After a miserable start to the campaign, the club's fortunes had been transformed by the appointment of Delio Rossi shortly before the winter break. Since the turn of the year, Samp had collected 18 points from nine games – conceding just three goals.

Ibarbo would double that figure in a single afternoon. Having opened the scoring after 18 minutes, the Colombian forward extended his team's advantage early in the second half, crashing the ball into the roof of the net from six yards after being left unmarked at a corner. In the 72nd minute he completed his hat-trick with a close-range header. Samp's only goal arrived in injury time, from a Maxi López penalty.

Cagliari will hope this game represents a breakthrough moment for Ibarbo, whose movement and explosiveness make him a handful to defend against but who had previously scored just once in 23 appearances this season. Although still young at 22 years old, his profligacy in front of goal had been a source of growing concern.

Neither Ibarbo nor his coaches made any comment after the game, the entire team having been placed into a press silence. The players spoke eloquently enough with their actions, though, running around the back of the stands at full-time in order to thank those fans who had cheered them on from outside the stadium. Andrea Cossu even scaled the fence to embrace one or two of them.

If Cagliari's supporters are not allowed into Is Arenas to see their team, then it seems that this team is prepared to come out of the stadium in order to see their fans.

Results and talking points

• Joining Ibarbo in the unlikely hat-trick scorers' club on Sunday was Parma's Amauri. The oft-mocked forward earned fresh opprobrium during the week after suggesting that he had not given up hope of representing Italy at the 2014 World Cup. To call that a long-shot would be to deal in gross understatement, but the player nevertheless deserves credit for dominating a Torino defence that had hitherto been one of the best in the division.

• Juventus took another large stride towards retaining their Serie A title, increasing their lead at the top of the division to nine points with a 1-0 victory over Catania on the same afternoon that Napoli lost 2-0 away to Chievo. It was hardly a resounding win for the champions, snatched by the substitute Emanuele in second-half injury time, but they won't mind one bit. The manager Antonio Conte insisted he would continue to take this season one game at a time, but with 10 games to go it is hard to envisage any other team claiming the Scudetto.

• The one less positive note for Juventus came from the stands, where a section of the crowd sang racist chants against Mario Balotelli before insisting once again that "there are no black Italians". The club has already been fined for such incidents this season, and although sanctions have not yet been decided there is a possibility the club could be forced to play their next fixture at a neutral site or behind closed doors as punishment.

• Napoli, meanwhile, are at risk of not only falling out of the Scudetto race but also losing their grip on second. Their lead over third-placed Milan is down to just two points after the Rossoneri beat Genoa on Friday, and it is hard to look past the form of Edinson Cavani when seeking an explanation for such a drastic turn of fortunes.

The striker is without a goal in eight games across all competitions, and his team is without a win in the last seven of those. Indeed, they have scored just two goals in that time. On Sunday Cavani missed a penalty early in the second-half which might have brought his team back into contention. It has been suggested that the player's poor form may be related to the fact that his wife, Maria Soledad, is presently back home in Uruguay, where she recently gave birth to their second son. Cavani has not seen her in weeks, and will likely not meet his newborn child until the international break in two weeks' time.

• As for Milan, their enjoyment of Friday's 2-0 victory was tempered only by an injury to Giampaolo Pazzini, who will miss Tuesday's Champions League last-16 second leg against Barcelona after suffering a deep bruise and micro-fracture in his right leg. The striker scored a tremendous goal to open the scoring shortly after picking up his injury, but the wisdom of his inclusion in the starting XI must be questioned. Mario Balotelli was freshly back from injury, and cup-tied for the game at the Camp Nou. As it was, the former Manchester City player replaced Pazzini after 25 minutes, and went on to score his team's second goal.

• Those are still better problems to have than the ones presently being faced by both Inter and Lazio. The Nerazzurri lost 1-0 at home to Bologna, and have collected just four points from their last four league games. Injuries and a misguided transfer policy have played a big role, but so has the manager Andrea Stramaccioni's excessive tactical tinkering. On Sunday alone his team seemed to rotate through several different formations in the space of a single half. Lazio also lost at home on Sunday evening, 2-0 to Fiorentina, and have won just one of their last eight league games.

• Worthy of recognition, despite his team's performance, was Javier Zanetti's 600th Serie A appearance. Gazzetta dello Sport named him as Inter's man of the match, though that was faint praise. "He gets this award by process of elimination," wrote Andrea Elefante. "He was the only one who didn't hurt his own team."

• Inter's supporters voiced their feelings about the club's recent transfer moves with a banner in the Curva Nord which read: "Why don't you give us a trial, too? You might find someone good. And at least they'd be an Inter fan."

• Lazio's fans, meanwhile, directed their ire at Michel Platini, following Uefa's decision that the team must play two European home games behind closed doors as a punishment for racist chants. "Heysel, 29-05-85," read the banner on display at the Stadio Olimpico this weekend. "You had the strength to carry on playing … the courage to celebrate in front of 39 dead. Platini, you pig, we won't take moral lessons from you."

• Palermo's fourth managerial change of the season should arrive sometime on Monday, when Gian Piero Gasperini is expected to lose the job for the second time this season. His most likely successor is thought to be Giuseppe Sannino – the man he replaced in first instance all the way back in September.

Results: Atalanta 2-1 Pescara, Cagliari 3-1 Sampdoria, Chievo 2-0 Napoli, Genoa 0-2 Milan, Inter 0-1 Bologna, Juventus 1-0 Catania, Lazio 0-2 Fiorentina, Palermo 1-2 Siena, Parma 4-1 Torino, Udinese 1-1 Roma.

The Latest Serie A table.