Defending champion AC Milan remained winless in Serie A following a 1-1 draw with Udinese on Wednesday, while 10-man Juventus drew 1-1 with Bologna to end its perfect start.
Antonio Di Natale took advantage of an error from Milan goalkeeper Christian Abbiati to give Udinese the lead in the 29th minute and Milan's 18-year-old forward Stephan El Shaarawy equalized in the 63rd after replacing Alexandre Pato, who came off after just 19 minutes with an apparent thigh injury.
Clarence Seedorf for Milan and Giampiero Pinzi for Udinese each hit the post at the San Siro.
In Turin, Mirko Vucinic took advantage of a quick free kick from Andrea Pirlo to put Juventus ahead in the 29th but then picked up his second yellow card just before the break for a hard foul and Daniele Portanova equalized for Bologna in the 52nd.
"I'm sorry not to have gotten the three points, but I'm satisfied for what the guys showed not just today but in the first three matches," said new Juventus coach Antonio Conte.
Meanwhile, Genoa beat Catania 3-0 to take over the top spot in the table, with previous leader Napoli losing 1-0 at Chievo Verona.
Rodrigo Palacio, who had been linked to a possible move to Inter Milan in the offseason, scored twice for Genoa and then set up a third goal for Kevin Constant.
Playing in a half-empty stadium, Napoli struggled to find inspiration after its 3-1 win over Milan on Sunday and Chievo's Davide Moscardelli took advantage of an error from defender Ignacio Fideleff to score in the 72nd.
"We didn't have one shot on goal and we lost the match," Napoli coach Walter Mazzarri said. "Losing happens and we're moving on."
Genoa, Juventus and Udinese each have seven points but Genoa leads on goals scored.
Napoli, Fiorentina, Palermo and Cagliari are one point behind the leaders, while Milan has just two points from three matches.
"Of course it's not nice to look at the standings and see that," Milan coach Massimiliano Allegri said. "But right now we've got 12 players injured and very few forwards. Tonight it was important not to lose, and we shouldn't look at the standings now."
Besides Pato, Milan was already missing forwards Zlatan Ibrahimovic and Robinho, plus midfielders Massimo Ambrosini and Gennaro Gattuso to injury.
Milan's 38-year-old forward Filippo Inzaghi came on for the final six minutes and nearly earned a penalty kick in added time.
Inter Milan is also struggling, and fired coach Gian Piero Gasperini after its 3-1 loss at newly promoted Novara on Tuesday. Claudio Ranieri has reportedly agreed to a two-year deal to replace Gasperini.
Having missed all of last season due to injury, Stevan Jovetic scored twice and Alessio Cerci added another as Fiorentina beat Parma 3-0.
Israel midfielder Eran Zahavi, Nicolas Bertolo and captain Fabrizio Miccoli scored for Palermo in a 3-2 win over Cagliari, which struck back with late goals from Daniele Conti and Rajda Nainggolan.
Also, Lazio rallied to win 2-1 at Cesena with second-half goals from Brazilian playmaker Hernanes and Germany forward Miroslav Klose after Adrian Mutu put the hosts ahead early with his first goal since transferring from Fiorentina.
Lazio coach Edy Reja had offered to resign Tuesday, but was asked to stay on by club president Claudio Lotito and the squad, which now has its first league win.
And having begun the season with a six-point penalty from a match-fixing and betting scandal, Atalanta moved back into the positive points with a 2-1 win over Lecce - giving the Bergamo squad one point from two wins and a draw.
On Thursday, Roma hosts Siena.