Fiorentina's perfect start to the season was ended by a late Mauricio Pinilla goal, which earned Cagliari a draw at the Stadio Artemio Franchi on Sunday.
Borja Valero gave the hosts the lead in the 71st minute and they seemed to be heading for a third straight win at the start of the Serie A season until substitute Pinilla headed the Sardinians level with a minute remaining.
As well as dropping two points, Fiorentina lost David Pizarro to a red card in stoppage time and both Juan Cuadrado and Mario Gomez to injuries which both required hospital treatment.
Genoa failed to reassure Sampdoria they had not authorised an undercover spying mission in midweek by putting their city rivals to the sword 3-0 in a derby victory at the Stadio Luigi Ferraris.
The build-up to the first Derby della Lanterna of the new season, from which both sides needed a first win, was shrouded in further intrigue as soon as camouflaged Genoa youth coach Luca de Pra was caught hiding in a wood next to Sampdoria's training ground.
De Pra, the nephew of famous Genoa goalkeeper Giovanni De Pra, was chased away while his club disavowed all knowledge of espionage tactics.
Whether or not the coach had divulged enemy secrets to his bosses may never be known, but Genoa's players were certainly well informed about their opponents' weaknesses on the night.
Samp were helpless to resist as Luca Antonini, Emanuele Calaio and Francesco Lodi all struck goals of real quality to break their club's duck for the season and earn the bragging rights for at least five months.
Lazio's players responded to an organised protest from disgruntled fans in the best way possible by strolling to a dominant 3-0 victory over Chievo in Rome.
Biancoceleste supporters expressed their disappointment over the club's perceived failures in the summer transfer market by leaving the Curva Nord empty for the start of Sunday's game.
A move for Galatasaray's Burak Yilmaz broke down before Libor Kozak was sold to Aston Villa, leaving Miroslav Klose as Lazio's only recognised striker, but first-half strikes from Antonio Candreva, Luis Cavanda and Senad Lulic proved there are goals throughout the team.
The capital club have now taken six points from three Serie A games while Chievo are yet to win a game.
Hellas Verona condemned fellow promoted side Sassuolo to their third consecutive defeat in Serie A with a 2-0 win.
Sassuolo may have won Serie B by three points from Verona in May but early impressions in the top flight would suggest the Modenese side are more likely to struggle.
Hellas trumped AC Milan with a brace from Luca Toni on the opening day and shrugged off the veteran striker's absence through injury to claim a second league win with goals from Raphael Martinho and Romulo.
Antonio Di Natale marked his 300th Serie A appearance for Udinese with a late goal to salvage a point from a 1-1 draw with Bologna at the Stadio Friuli.
The 35-year-old, who made his top-flight debut for the Bianconeri in 2004, notched his 159th league goal for the north-east club after Alessandro Diamanti had put Bologna on track for their first win of the new season.
The point keeps European hopefuls Udinese in a healthy position in the fledgling league table while Stefano Pioli's Bologna are floundering in the bottom half with only two points on the board.
Livorno picked up their second successive win with a 2-0 victory over Catania thanks to two goals from Paulinho and numerous saves from goalkeeper Francesco Bardi.
The Brazilian forward struck in the 66th and 72nd minutes before Bardi preserved the points to take Livorno into the top half of the table and leave Catania rooted to the foot of it with their third straight defeat this season.
The pressure therefore increases on Catania coach Rolando Maran, although he will wonder, like many, how his side failed to find the back of the net at the Stadio Armando Picchi.
On Saturday, Napoli played the waiting game to move to go top with a 2-0 win over Atalanta at the Stadio San Paolo.
Rafael Benitez's side were made to work hard for the points against a resilient Nerazzurri side, whose hopes of holding out evaporated once Luca Cigarini was sent off soon after Higuain had sent the home fans into delirium.
Jose Callejon wrapped up victory late on to extend Napoli's 100 per cent start to the season.
Inter Milan and Juventus shared the spoils from the first Derby d'Italia of the new Serie A season as Arturo Vidal salvaged a 1-1 draw for the reigning champions.
Both clubs had claimed maximum points from their opening two matches, but Inter have looked the more confident side under new boss Walter Mazzarri, who arrived from runners-up Napoli.
Indeed it was the home side who broke the deadlock midway through the second half at San Siro as substitute Mauro Icardi scored his first goal in Nerazzurri colours, but Chilean midfielder Vidal - already a two-time Scudetto winner with Juve - responded with his 20th league goal for the Turin giants.