Who is best placed to challenge a struggling Juventus in Serie A?

Fiorentina are currently top of the Serie A after beating Inter Milan

As Fiorentina went top of Serie A for the first time since the days of Gabriel Batistuta and Rui Costa, it perhaps indicated just how open the race for the Scudetto is going to be this season. Not since 1999 had La Viola been atop the summit of Italy's top flight – such was the impact of their 4-1 win over Internazionale at the San Siro on Sunday.

Inter had started the season with five wins in a row. But after suffering a horrendous opening 45 minutes, they were soundly beaten by Paulo Sousa's team. Goalkeeper Samir Handanovic gifted the visitors a penalty in the fourth minute when his poor touch caused him to fell Nikola Kalinic and this signalled the shape of things to come for the home team. Miranda was also given a red card after half-an-hour, putting paid to any hope Roberto Mancini had of masterminding a recovery from a three-goal deficit.

Kalinic, maybe remembered in England for an underwhelming spell at Blackburn Rovers over four years ago, bagged a hat-trick that ensured a comfortable victory for Fiorentina. His team's early dominance was enough, and they barely looked troubled by the host's meagre fightback in the second half.

Sousa was originally an unpopular choice to replace Vincenzo Montella as manager, but there will be no complaints in Florence now as they lie top after six games. Level with Inter on 15 points, the Portuguese coach has quietly imprinted his philosophy on the team, overhauling their style of play to the point where they have shown they are more than capable of capturing a European place.

Defending champions Juventus in bad shape

The make-up of the top five in Serie A was perhaps not expected half-a-dozen games into the season. Granted, it is only six games, but by now we should probably be seeing the main title contenders putting any early-season teething problems aside by edging their way up the rankings.

Up to this point, the narrative had been framed by reigning champions Juventus' woeful start to the season. Now, their stuttering form and the reasons for it have been exposed, and the concentration can move towards who is in a position to capitalise effectively whilst the Bianconeri address their issues.

Will Juventus trust Massimiliano Allegri to navigate the club through the current crisis?

Their rivals need to ensure any recovery made by Massimiliano Allegri's team – if they stick by their beleaguered manager that long – arrives too late, and the pressure becomes too much for even the might of the Old Lady to overcome.

The top four is currently completed by Torino and Sassuolo – two teams who both look to have built on their safe mid-table showings last campaign. Although it would be unlikely both could remain there for the long term, their presence in the top four indicates Juventus and Roma will certainly not have it their own way when trying to take back positions in the league that they will feel are rightfully theirs.

Can Roma overcome injury crisis?

Having strengthened wisely in the summer, many touted Roma as the main threat to the Juventus domination. They are safely poised in sixth, only four points behind Fiorentina and Inter, but criticism of their recent displays has been building.

Having now been hit by the news that Francesco Totti, Seydou Keita and new signing Edin Dzeko will, on first evaluation, be out for at least a couple of weeks, the games are coming fast for manager Rudi Garcia. He may find that these untimely injuries prevent him from reviving his team's inconsistent start.

Rudi Garcia has an injury crisis at Roma

Similar to last season, Roma remain difficult to beat, but they also still struggle to see off seemingly inferior opponents. They lost only six times in 2014/15, but it was the 13 draws that doomed their title tilt to failure. Losing only to Sampdoria so far this time around is not the main issue, it is the inability to see off the likes of Sassuolo and Verona that will concern the Giallorossi at the moment.

Despite winning their last two, fifth-placed Lazio also give the impression they are merely stumbling along at present. Their fans are restless and will demand their away form improves considerably over the next few weeks.

Juventus’ disappointing start is welcomed by many, and the door is open in Serie A for someone to make a tangible effort of wrestling the title from their grasp. Fiorentina have made their first move by handing Inter their first defeat of the season. It is up to the rest to now make theirs.