Juventus missed the chance to overtake surprise Serie A leaders Sampdoria when they were held 1-1 at home by Bologna on Sunday.
Brazilian forward Adailton sidefooted home a cross from the left deep in injury time to deny the Turin side, who had ridden their luck after French forward David Trezeguet prodded them in front from close range on 24 minutes.
Juve are second with 14 points from six games, one fewer than Sampdoria, who beat Inter Milan 1-0 in Genoa on Saturday.
Marco Storari saved AC Milan from yet another embarrassing defeat as they only just managed to hold a lively Bari to a goalless draw at the San Siro. Bari attacked from start to finish and will wonder how they did not manage to come away from Milan with all three points as the Rossoneri once again disappointed in front of their own fans, who let their feelings known at the final whistle.
The draw leaves Leonardo's men seven points behind league leaders Sampdoria in the wrong half of the table with Bari just one point further behind.
Daniele De Rossi's last-gasp equaliser handed Roma a share of the spoils in their Serie A game at Catania.
The Sicilian outfit thought they had claimed their first triumph of the campaign courtesy of Takayuki Morimoto's first-half goal, only for De Rossi to ruin the party deep in stoppage time. Catania finished the game a man light after substitute Gennaro Delvecchio was handed his marching orders for dissent soon after Roma restored parity.
A late goal from Mauro Zarate spared Lazio's blushes at the Stadio Olimpico as the Romans salvaged a point against Palermo.
The hosts looked to be heading for their third consecutive home defeat of the season following substitute Edison Cavani's 75th minute opener for Palermo. But Zarate popped up in the final five minutes to snatch a share of the spoils for Lazio.
Marek Hamsik struck twice in the second half at San Paolo to hand Napoli a second win of the season, 2-1, at the expense of struggling Siena and ease the pressure on Roberto Donadoni.
Two late goals gave Udinese all three points as they leapfrogged opponents Genoa in Serie A. Antonio Di Natale netted his eighth goal in six games in the 82nd minute to unlock a tight game, before Simone Pepe secured all three points one minute from the end.
A solid 2-0 performance from Cagliari at in-form Parma gave the Sardinians a deserved second victory on the trot amid hopes they have finally kick-started their season. Jeda got them off to the perfect start with his seventh-minute goal and Daniele Dessena doubled his side's advantage shortly before the hour mark.
Atalanta continue the search for their first win of the Serie A season with Chievo ensuring the points were shared at the Stadio Marc Antonio Bentegodi.
Simone Tiribocchi broke the deadlock for the visitors, but their lead lasted just five minutes with Sergio Pellissier hitting back for Chievo. The draw was not enough to move Atalanta out of the bottom three, while Chievo sit eighth in the standings.