Juventus drew 1-1 at bitter rival Inter Milan in their first Serie A clash at an electric San Siro on Saturday, while Napoli moved atop of the table with a 2-0 home win over Atalanta.
A dramatic finale at Torino saw AC Milan come from behind to draw 2-2 thanks to two very late goals, including another Mario Balotelli penalty.
Mauro Icardi scored his first goal for Inter to put the hosts ahead in a fixture known as Italy's derby. However, Arturo Vidal levelled almost instantly for Juventus — as Inter conceded its first goal this season.
"The match confirmed today that Inter can target the top of the table this season, and that Juventus is a team which is very tough to beat," Juventus coach Antonio Conte said after his 100th match in charge. "I saw my team play very well in a difficult stadium against a side that can compete in everything right to the end, seeing as they don't have European commitments.
"What I liked best was the effort and desire to do well."
Inter coach Walter Mazzarri was also pleased how his side reacted to the pressure.
"I saw positive responses, which is a reason to be proud," Mazzari said. "Some of the lads felt the situation too much at the beginning, faced with the top team, in a full stadium ...
"Are we a title-winning team? You only need two bad matches and everything changes. It's not time to make those judgments now."
Inter took the lead in the 73rd when Ricky Alvarez robbed Giorgio Chiellini and burst forward before putting in a through ball for substitute Icardi to run onto and smash home — sending most of the 83,000 crowd into a frenzy. Icardi scored three goals against Juventus for Sampdoria last season.
However, Vidal levelled 80 seconds later, catching the Inter defence napping as he drilled Kwadwo Asamoah's cross into the bottom right corner.
Juventus almost took the lead moments later but Carlos Tevez fired just past the right upright.
Napoli moves up
In Naples, Napoli's new signings were again on target to help the team maintain its 100 per cent record after three games.
Gonzalo Higuain scored his second goal in as many games since his moved from Real Madrid, to give the home side a 71st-minute lead and Jose Callejon, who also joined from Madrid, scored his third goal for his new club 10 minutes later.
Former Napoli midfielder Luca Cigarini was sent off in the 74th for a second booking for a bad tackle on Callejon.
At Torino, all eyes were on Kaka in his first game for Milan since 2009 after returning from Real Madrid. The Brazilian wore the captain's armband for part of his debut after Riccardo Montolivo was forced off injured.
Milan appeared to be heading for its second defeat of the fledgling season after goals from Danilo D'Ambrosio and Alessio Cerci before the game changed with a somewhat fortunate goal for the visitors three minutes from time.
Torino goalkeeper Daniele Padelli punched the ball clear and Sulley Muntari scuffed his shot but the ball took a deflection and rolled into the bottom left corner. Torino thought the goal had been disallowed because Balotelli appeared to be offside and confusion reigned before it was awarded to much protest from the home players.
Matters grew worse for Torino in stoppage time when Milan was awarded a penalty after Giovanni Pasquale tripped Andrea Poli. Balotelli, who has never missed a penalty in his career, stepped up to convert his 26th spot kick and snatch a point with the last kick of the game.
"Four minutes from the end we'd lost this, but the lads did well to believe," Milan coach Massimiliano Allegri said. "Torino played well, caused us a lot of problems and we left ourselves too open to their counterattacks.
"We have changed some things in our system, so it takes time to rediscover our balance. At the moment we are too soft in defence — by which I mean the whole team is not effective enough when defending. It's not good enough."