TURIN, Italy (AFP) - Disgraced former Italian champions Juventus moved seven points clear at the top of Serie B after a 2-0 victory over Napoli on Tuesday.
The match was marred by clashes between rival supporters outside the Olympic Stadium ahead of the afternoon kick-off.
A fan was hospitalised after being stabbed in the leg.
The man was rushed to hospital but was not reported to be seriously injured, according to the Ansa news agency.
It was a sorry beginning to a match that had great significance in the promotion race as Napoli are one of Juve's main rivals.
Juventus dominated the early running and took the lead on 18 minutes as Italian midfielder Mauro Camoranesi headed home a cross from Czech counterpart Pavel Nedved despite a tight angle.
Camoranesi was involved again in the second goal as his cross was turned home by Juve captain Alessandro Del Piero four minutes after the break.
Juve were forced to hold on with 10 men after Claudio Marchision was sent-off on 62 minutes after throwing a punch at an opponent.
The league leaders survived without too many scares though and moved seven points clear of Genoa with Napoli a further two points back.
But the crowd trouble will have come as unwelcome news for Italian football which is already reeling from a flurry of recent incidents.
The Italian government last week passed new laws they hope will stamp out football hooliganism.
Strict new security measures were introduced shortly after a policeman was killed when Catania fans went on the rampage before, during and after their Serie A derby match against Sicilian rivals Palermo in February.
There was also trouble between Roma and Manchester United fans ahead of last week's Champions League quarter-final first leg tie with several United fans being stabbed before the game.
The government clampdown demanded clubs took more responsibilty for security, including more closed-circuit television (CCTV) cameras at stadiums, named tickets, electronic turnstiles, adequate stewarding, and crowd filtering areas outside grounds.
Juventus were last summer demoted from Serie A and given a nine-point handicap in Serie B for their role in the Italian match-fixing scandal.
|Thiago Silva eyeing PSG exit amid criticism|
|Premier League or Champions League title will take Spurs to ´different level´ – Pochettino|
|Klopp: Bayern Munich move would´ve been complicated|
|Wenger names Vieira as potential Arsenal successor|
|Simeone demands more alert Atletico to solve away day problems|
|Malaga relegated from LaLiga after late defeat|
|Conte reaches 100 Chelsea games with win at Burnley|
|When I fail, I get really angry - Morata apologises for tantrum|
|Neymar names players to watch at World Cup|
|Hughes remains upbeat despite Leicester draw|
|Two strikers an FA Cup option for Conte´s Chelsea|
|I´m not finished, Chelsea captain Cahill insists|
|Leicester City 0 Southampton 0: Saints´ survival bid suffers fresh blow|
|Burnley 1 Chelsea 2: Conte´s men boost top-four chances with FA Cup warm-up|
|Fenerbahce-Besiktas abandoned after Gunes struck by object thrown from crowd|
|Real Sociedad 3 Atletico Madrid 0: Barca´s title party set to start|
|Carrick reveals depression led to England exile|
|´Who are they?!´ - Accrington milk promotion with supermarket stunt|
|Conte names Hazard on bench for Burnley clash|
|Rooney denies rift with Everton boss Allardyce|
|Kane will leave Tottenham unless they win trophies, predicts Souness|
|Portugal´s Sanches has no chance of World Cup selection - Carvalhal|
|Better with one arm - Julio Cesar reveals Mourinho´s Casillas jibe|
|Mourinho has nothing to prove - Pochettino|
|I have spoken to the chairman - Allardyce upset by Everton survey|
|Emery dismisses talk of Real Sociedad offer|
|Sidibe´s Monaco season over but World Cup return possible|
|Guardiola thanks ´unique´ City staff in celebration speech|
|Wan-Bissaka signs long-term Crystal Palace extension|
|Rakitic to make comeback following finger surgery|
|FIFA dismisses Brewster racism complaint from U-17 World Cup final|
|Isak could benefit from Batshuayi injury - Stoger|
|Shaw hopes to have earned FA Cup start|
|Mercado: If I smack Messi, I can´t go back to Argentina!|
|Salah wants Golden Boot to prove Chelsea doubters wrong|
|Chelsea´s Alonso gets three-game ban for Long challenge|
|Atletico clash absolutely vital to Arsenal´s season, admits Wenger|
|Wenger still confident Wilshere will sign new deal|
|Guardiola a friend as well as a boss, says Walker|
|Heaton: Europe a realistic possibility for Burnley|
|Late charge for the Golden Boot! - Smalling jokes about goalscoring form|
|Emery unsure when PSG star Neymar will return|
|Marcelo backs Ronaldo to extend scoring run for Madrid|
|Copa Libertadores Review: Libertad preserve 100 per cent record, Corinthians stay unbeaten|
|Man United should have 10 more points – Mourinho laments inconsistency|
|Gombau sacked by Western Sydney Wanderers|
|Rafael: Van Gaal told me I could leave United after one-minute meeting|
|Klopp told Liverpool they could train naked because of Salah|
|Zidane denies Bale problems, defends Benzema|
|Sarri: Napoli won´t change approach against Serie A rivals Juve|
|PSG will respect Les Herbiers, assures Emery|
|Chelsea boss Conte: It´s easier for Dyche at Burnley|
|It will be a great game - Allegri prepared for title showdown with Napoli|
|Maybe it is my fault - Gattuso takes responsibility for AC Milan´s winless run|
|Kovac insists Frankfurt are united amid Bayern row|
|Not a single doubt for Madrid ahead of Bayern clash, claims Lucas|
|Real Madrid 1 Athletic Bilbao 1: Kepa heroics torment Madrid until Ronaldo leveller|
|Mourinho salutes Pogba display|
|Caen 1 Paris Saint-Germain 3: Mbappe double keeps treble hopes alive|
|Burnley boss Dyche could manage England, says Heaton|
|Napoli 4 Udinese 2: Scudetto race alive ahead of tantalising Turin trip|
|Torino 1 AC Milan 1: Donnarumma error proves costly|
|Schalke 0 Eintracht Frankfurt 1: Kovac to face Bayern Munich in DFB-Pokal final|
|Crotone 1 Juventus 1: Nwankwo stuns Serie A leaders with spectacular equaliser|
|Bournemouth 0 Manchester United 2: Red Devils bounce back as Mourinho´s changes pay off|
|Bong stands by complaint despite Rodriguez racial abuse verdict|
|Martial and Darmian start as Mourinho makes seven Manchester United changes|
|Heaton relishing Burnley battle with Pope|
|Aubameyang ´wasn´t sure´ about Lacazette|
|A mid-season break in England would make a great difference, insists Conte|
|Tottenham trophies would follow FA Cup success - Vertonghen|
|If anyone can beat Real Madrid, it´s Bayern - Rummenigge|
|Barton to take charge at Fleetwood Town|
|Simeone still hopes Griezmann will stay at Atletico Madrid|
|Aguero will not be 100 per cent for World Cup - Argentina doctor|
|De Bruyne leads new Premier League Playmaker award|
|Man City are set up to dominate, says Conte|
|AFC Champions League Review: Shanghai SIPG beaten, Jeonbuk & Tianjin end with wins|
|PFA Premier League Team of the Year in Opta numbers|
|Neymar will be a World Cup great, says Serginho|
|England need a miracle to win World Cup - Walker|
|PFA Premier League Team of the Year: Aguero earns place for first time|
|Kaka opens up on ´respectful but complicated´ Mourinho relationship|
|FFP not there to kill clubs, insists UEFA president Ceferin|
|Ibrahimovic: I´m going to the World Cup|
|Tottenham star Kane ´not bothered´ by goal appeal backlash|
|Matthaus praises Bayern-bound Kovac|
|Copa Libertadores Review: Del Valle hat-trick lifts Millonarios|
|Toronto 1 Guadalajara 2: Pulido free-kick sees visitors grab win|
|He is confident and brave – Dida hails Alisson improvement|
|Nothing can tarnish Buffon´s career – Lippi|
|Valverde defends Barcelona rotation|
|Barca set another LaLiga record with 33-match run|
|Hat-trick hero Muller credits Ulreich after thrashing Leverkusen|
|Icardi should not be happy - Spalletti demands more from free-scoring Inter captain|
|Suarez relieved to keep Barca run going|